TMPRSS2 and COVID-19: A range of cultured human cells relevant to SARS‐CoV‐2 infection (i.e., airway) and/or COVID‐19 pathophysiology (i.e., vasculature) were assessed for expression of host entry proteins ACE2 and TMPRSS2 at the mRNA level, and expression was regulated by estradiol and apelin‐13, as expected (Table 1).