CCR5 and viral infectious disease: Here, taking into consideration the results previously described for some polymorphisms of TMPRSS2 and CCR5 genes in different human populations (see above), we analyzed three polymorphisms (rs35074065, rs12329760, and rs333) to detect the presence of an allele or a genotype that could confer resistance to viral infection and/or result in less severe symptoms of COVID-19 disease.