One of the genetic predisposing factors, besides the expression of ACE 2 and the protein associated with it, can be genotypes HLA-A*02:01 and HLA-A*03:01, associated with a low probability of developing a severe form of COVID-19 [80], and HLA-DRB1*04: 01 associated with asymptomatic infection [81] (Figure 2). Here, HLA-DRB1 is linked to COVID-19.