ABO and COVID-19: These include the identification of two genetic susceptibility loci associated with respiratory failure in COVID-19, including the ABO locus in chromosome 9 and a gene cluster at chromosome 3 [16], population-specific variation of the coding variants of Angiotensin-converting enzyme 2 (ACE2), the SARS-CoV-2 receptor for host cell entry [17,18,19] and that of the COVID-19 risk haplotype originating from Neanderthal genomes [20].