ABO and COVID-19: We identified nine genes (ABO, CCR2, CXCR6, FYCO1, IFNAR2, IL10RB, LZTFL1, OAS1, and OAS3) with evidence of allelic imbalance at COVID-19 GWAS risk variants, with three genes (ABO, OAS3, and IL10RB; see Supplementary Fig. 2 and Supplementary Data 4) when restricted to leading GWAS index variants (p value <0.05/21).