A team of scientists at New York University and the Icahn School of Medicine at Mount Sinai were the first to report finding genes possibly tied to resistance to Covid-19. In early 2020, Benjamin tenOever, a professor of microbiology at Mount Sinai, along with Neville Sanjana, an assistant professor of biology at NYU, and colleagues at the New York Genome Center set out to sort through the potential genetic factors underlying Covid resistance. To do this, they used CRISPR genome editing technology to disable each of the 20,000 human genes in lung cells and then exposed them to SARS-CoV-2. Most of the cells died within a few days. “Anything that lives,” tenOever explained, “is clearly missing something essential for a virus, and so potentially has a significant gene mutation.”

In January 2021, the group published a paper in Cell, reporting that RAB7A, a gene important for the movement of cargo from inside the cell to the cell surface, topped their quantitative ranking of genes the coronavirus can’t do without. Inhibiting RAB7A reduces SARS-CoV-2 infection because the gene ensures ACE2 receptors are retained inside the cell, making them unavailable as the required point of attachment for the spike protein of SARS-CoV-2 (which attaches and then enters the cell).

Although mutations in RAB7A are very rare, according to Sanjana, drugs that inhibit this gene or others required for viral infection could, in theory, be used as a treatment or even be used as a post-exposure prophylactic.