Gain-of-function (GOF) research is a broad category of scientific work in which a pathogen, toxin, or other biological agent is deliberately modified to enhance one or more of its biological properties — most consequentially, its transmissibility or virulence in a host species. Most gain-of-function work is routine and low-risk: altering a bacterium’s antibiotic resistance for a mechanistic study, or a virus’s ability to infect a cell line, are technically “gain-of-function” but pose no elevated public-health risk and are reviewed like any other laboratory protocol. A much narrower subset — often labelled GOF research of concern (GOFROC) or, in current US federal policy, research producing an enhanced potential pandemic pathogen (ePPP) — is subject to a distinct, higher tier of institutional and federal oversight because the modified agent could plausibly cause a pandemic if it escaped containment or were misused. This guide covers what distinguishes ordinary gain-of-function work from the regulated subset, why the research is conducted at all, and the US oversight framework research administrators need to know, including the significant 2025 policy change still working through implementation as of this writing.
What Makes Research “Gain-of-Function”
Operationally, a study is gain-of-function research when its design intentionally increases a biological agent’s capability relative to its baseline — commonly transmissibility, virulence, host range, immune evasion, or resistance to a countermeasure (antibiotic, antiviral, vaccine). The term describes a research technique, not a risk category by itself: the same label applies to a benign yeast-genetics experiment and to work on an agent capable of causing a pandemic. What separates the two, for oversight purposes, is not the phrase “gain of function” but a separate, narrower definition.
Executive Order 14292, “Improving the Safety and Security of Biological Research” (May 5, 2025), defines dangerous gain-of-function research as scientific research on an infectious agent or toxin with the potential to cause disease by enhancing its pathogenicity or increasing its transmissibility. The predecessor federal framework used a related but distinct concept, the enhanced potential pandemic pathogen (ePPP) — a pathogen resulting from the enhancement of transmissibility or virulence in humans, explicitly excluding pathogens that occur naturally and are simply being studied, cultured, or characterized without modification. A pathogen that is already highly transmissible or virulent in nature is not, by virtue of that fact alone, an ePPP; the oversight trigger is the deliberate enhancement, not the agent’s baseline danger.
Why the Research Is Conducted
Gain-of-function work of the regulated kind is a small fraction of infectious-disease research overall, and institutions and funders that permit it generally justify it on specific scientific grounds: understanding which mutations could allow an animal virus to jump to and spread among humans (informing pandemic-preparedness surveillance), characterizing how a pathogen might evolve resistance to a vaccine or antiviral before that resistance appears naturally, and developing and validating countermeasures against plausible future variants. The oversight frameworks described below do not prohibit this research; they require that its potential benefits be weighed against biosafety and biosecurity risk, on a protocol-by-protocol basis, before it is funded or conducted.
US Federal Oversight: From the 2014 Pause to the 2025 Executive Order
The current oversight regime is the product of roughly a decade of iterative federal policy, not a single static standard:
- 2014 — funding pause and DURC Policy. Following biosafety incidents and a series of controversial gain-of-function influenza studies, the US government paused federal funding for GOF research involving influenza, MERS, and SARS viruses while it developed a formal review framework, and separately issued the 2014 Dual Use Research of Concern (DURC) policy governing research that, while legitimate, could be misapplied to cause harm.
- 2017 — the P3CO Framework. HHS adopted the Potential Pandemic Pathogen Care and Oversight (P3CO) Framework, a pre-funding, multidisciplinary review process specifically for proposed research reasonably anticipated to create, transfer, or use an enhanced potential pandemic pathogen. Review weighed anticipated scientific and public-health benefit against biosafety/biosecurity risk and available risk-mitigation measures before an agency could fund the work.
- 2024 — the unified DURC/PEPP Policy. The “United States Government Policy for Oversight of Dual Use Research of Concern and Pathogens with Enhanced Pandemic Potential” combined and updated the 2014 DURC policy and the 2017 P3CO Framework into a single structure built around two review categories. Category 1 — the broader, more consequential tier — captures all research involving agents/toxins regulated under the Federal Select Agent Program, plus any human pathogen recommended for BSL-3 or BSL-4 handling under the CDC/NIH Biosafety in Microbiological and Biomedical Laboratories (BMBL) manual, when the research meets specified criteria for enhancing transmissibility or virulence. Category 2 covers a narrower slice of work meeting a lower risk threshold. Institutions were expected to establish an Institutional Review Entity (IRE) to conduct local pre-review, feeding into agency-level and, for the highest-risk work, interagency (Review Group-level) review before funding could proceed.
- May 5, 2025 — Executive Order 14292. Before the 2024 policy’s effective date, the administration issued EO 14292, which superseded the pending 2024 framework, immediately paused federally funded research meeting the EO’s “dangerous gain-of-function research” definition, and directed the Office of Science and Technology Policy (OSTP) to deliver a successor policy within 120 days. The EO separately directs an end to federal funding of dangerous gain-of-function research conducted by foreign entities in countries of concern, and tasks OSTP with developing, within 180 days, a strategy — including nucleic-acid-synthesis screening — to govern gain-of-function research that occurs without federal funding, which the pre-existing framework did not reach.
Current status: as of this writing, CASRAI could not independently confirm whether OSTP’s successor policy (due under the EO’s 120-day clock, roughly September 2025) has been finalized and published, or what its final Category 1/Category 2 structure looks like relative to the 2024 policy it replaces. Research administrators and Institutional Biosafety Committees working in this space should treat the specifics above — particularly category definitions and IRE mechanics — as the most recent full framework on record, and verify current status directly against ASPR’s oversight framework page and NIH Guide notices before relying on them for an active protocol.
How Institutional Review Fits Together
Gain-of-function oversight does not replace an institution’s ordinary biosafety review — it adds a layer on top of it. A protocol involving an enhanced potential pandemic pathogen still goes through the standard Institutional Biosafety Committee (IBC) process under the NIH Guidelines for Research Involving Recombinant or Synthetic Nucleic Acid Molecules, with containment assigned per the BMBL (up to BSL-4 for the highest-consequence agents). DURC/PEPP or dangerous-gain-of-function review is additional and complementary: it asks a different question — not “is this contained safely?” but “should this research, and its anticipated results, be funded and published at all, given dual-use risk?” — and for Category 1-equivalent work, that question is answered above the institution, at the federal agency or interagency level, not by the IBC alone.
Related Concepts
For the containment mechanics underlying any GOF or ePPP protocol, see CASRAI’s entries on Biosafety Level (BSL), BSL-3, and BSL-4. Gain-of-function research is a subset of the broader dual-use research of concern (DURC) category — most GOF work of concern is also DURC, though not all DURC involves gain-of-function techniques (e.g., publishing a detailed synthesis protocol for a dangerous toxin is DURC without any enhancement of the agent itself).
Frequently Asked Questions
Is all gain-of-function research dangerous or restricted?
No. The technique of enhancing a biological agent’s properties is used constantly in ordinary, low-risk laboratory research — most gain-of-function studies never touch the regulated ePPP/dangerous-GOF category and are reviewed like any other protocol through the institution’s IBC.
What is the difference between gain-of-function research and an enhanced potential pandemic pathogen (ePPP)?
Gain-of-function is the technique (deliberately enhancing a property of an agent); ePPP is a specific regulatory classification for the subset of resulting pathogens whose enhanced transmissibility or virulence in humans triggers the highest tier of federal review. A pathogen that is dangerous in its natural, unmodified state is not automatically an ePPP.
Who reviews gain-of-function research proposals before they’re funded?
Historically, review ran through an institutional pre-review body (most recently termed an Institutional Review Entity under the 2024 policy) feeding into federal agency and, for the highest-risk work, interagency review — separate from and in addition to standard IBC biosafety review. The exact review body and process are in transition following the May 2025 executive order; institutions should confirm the current mechanism with their biosafety office.
Does gain-of-function oversight apply outside the United States?
This guide covers US federal policy specifically. Other countries and international bodies (including the WHO) have separate biosafety and dual-use oversight structures; a multinational collaboration should confirm which jurisdiction’s framework governs the work being performed in each location.
