TMPRSS2 and systemic lupus erythematosus: The opposite happens in children, in whom theACE2gene in the lungs and other tissues is hypermethylated and, therefore, silenced.54This suggests that certain subgroups of patients with known epigenetic features are more susceptible to SARS-CoV-2, such as those with systemic lupus erythematosus (SLE), in whom a strong overexpression of the lung protein ACE2 seems to be related with hypomethylation.55Pique-Regi et al.56showed that the placenta expresses negligible amounts of both ACE2 and TMPRSS2, which could explain the scarcity of reported infections between mother and child in utero.