The K18‐hACE2 transgenic mouse strain is a preclinical animal model originally established for studying SARS‐CoV‐1 pathogenesis [23], but has been instrumental in revealing the complex host immune responses to SARS‐CoV‐2 due to its ability to recapitulate the major COVID‐19 manifestations in humans [24, 25, 26, 27]. The gene discussed is KRT18; the disease is COVID-19.