ABO and COVID-19: Significant results were obtained from the Severe COVID-19 GWAS Group headed by A. Franke and T. Karlsen from genomewide association study (GWAS) of severe COVID-19 with respiratory failure.21 They identified gene variants in two areas of the human genome that are associated with COVID-19-related death: locus 3p31.21 being associated to the disease susceptibility gene cluster, and locus 9q34.2 that coincides with the ABO group; the latter confirming ABO blood group system involvement as a genetic factor involved in COVID-19 pathogenesis as described above.