TMPRSS2 and COVID-19: Several epidemiological studies revealedACE2gene variations that alter the amino acid sequence of the receptor protein can affect interindividual variability and susceptibility to COVID-19 in populations.3, 4, 5Similarly, variations in transmembrane protease serine 2 (TMPRSS2) that is involved in priming SARS-CoV-2 by cleaving the S protein at the S1/S2 and S2 sites were shown to affect susceptibility of individuals to be infected with the virus by altering or initiating cell entry.6, 7