The most replicated result so far associated variants on chromosome 3 near LZTFL1 and SLC6A20 genes with infection, hospitalization, and critical illness, as well as ABO gene on chromosome 9 correlating non-O blood type with a higher rate of infection and severe disease (Ellinghaus et al., 2020; COVID-19 Host Genetics Initiative, 2021; Pairo-Castineira et al., 2021; Shelton et al., 2021; Thibord et al., 2022). The gene discussed is SLC6A20; the disease is infection.