Furthermore, using these GWAS data, we and Katz et al. (in a preprint) (Katz et al., 2020; Karim et al., 2020) had previously linked the ABO signal with CD209/DC-SIGN protein, clotting factors, coagulation disorders, and concentrations of IL-6, all potential risk factors for COVID-19. This evidence concerns the gene ABO and blood coagulation disease.