Gain-of-function research
Gain-of-function research (GoF research or GoFR) is medical research that genetically alters an organism in a way that may enhance the biological functions of gene products. This may include an altered pathogenesis, transmissibility, or host range, i.e., the types of hosts that a microorganism can infect.
Source: Wikipedia — Gain-of-function research (CC BY-SA 4.0)