TMPRSS2 and COVID-19: Owing to the observation of androgen deprivation therapies (ADTs) decreasing transmembrane protease serine 2 (TMPRSS2) levels (often overexpressed in prostate cancer) and offering partial protection against COVID-19, a possible mechanism for this was postulated to be due to androgen receptor activation that upregulates transcription of the TMPRSS2 [27,28,29].