TLR7 and COVID-19: Recessive or incompletely dominantloss-of-function mutations of TLR7 and other X-chromosomalgenes such as ACE2 (that encodes angiotensin-converting enzyme2, the cellular receptor for SARS-CoV-2) and NEMO (encodesNF-kappa-B essential modulator, a regulatory protein involved in antiviralresponse) may be partly responsible for the higher risk of severe COVID-19 andhigher death rates in men compared to women (Espinosa et al., 2020; Patil etal., 2020).