The so-called “gain of function” research has been recently debated in the context of viral research on coronaviruses and whether it is too risky to undertake such experiments. However, the meaning of “gain of function” or “GOF” in a science policy context has changed over time. The term was originally coined to describe two controversial research projects on H5N1 avian influenza virus and was later applied to specific experiments on coronavirus. Subsequent policies and discussions have attempted to define GOF in different ways, but no single definition has been widely accepted by the community. The fuzzy and imprecise nature of the term has led to misunderstandings and has hampered discussions on how to properly assess the benefit of such experiments and biosafety measures.

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