TYK2 and COVID-19: In addition, a 19p13.2 locus, where the TYK2 gene is located, was also associated with patients with critical COVID-19 (Pairo-Castineira et al., 2021; COVID-19 Host Genetics Initiative, 2021; Horowitz et al., 2022; Kousathanas et al., 2022; Degenhardt et al., 2022).