Several single-nucleotide polymorphisms of the ACE-2 gene have been observed to be associated with hypertension and other cardiovascular diseases [22] and could influence susceptibility to SARS-CoV-2 infection, especially c.513-1451G>A (rs2106806) and c.15643279T>C (rs6629110) polymorphisms [23] and G>A changes at nucleotide +4 of intron 3 (rs2285666), showing that GG and TT genotypes are significantly more susceptible to severe outcomes of COVID-19 [24]. Here, ACE2 is linked to COVID-19.