APOE and COVID-19: They recognized that some genetic mutations were linked to protection against COVID-19 (as HLA-A*30 and CCR5 rs333Del), others could be risk factors as APOE rs429358C allele or deteriorate the outcome of COVID-19 as HLA-B*38, HLA-C*6, and ApoE rs429358C alleles were associated with risk for severe forms of COVID-19.