Gain-of-function research involves giving a pathogen a new "ability" and is controversial because if a pathogen is mutated to become more infectious or deadly and then escapes from a lab, it could ...

We need to ban some gain-of-function research on deadly viruses. We also need a better definition of what it is we're banning.

Gain-of-function research is the serial passaging of microorganisms to increase transmissibility, virulence, immunogenicity, and host tropism.