HDAC9 and lung adenocarcinoma: The levels of both ACE2 and renin were analyzed in the following cell lines representing an example of tissue preferentially affected by the SARS-CoV-2 virus: human lung adenocarcinoma A549 cells, human intestinal adenocarcinoma HT29 cells (nontreated and differentiated by the HDAC inhibitor sodium butyrate (NaBt), human embryonal kidney cells HEK293, and mouse embryonic stem cells (mESCs; line D3).