The presence of the entry factors ACE2 and TMPRSS2 in cancer cell lines of various origins is in accordance with their expression in corresponding primary tissue, where ACE2 and TMPRSS2 were detected in cells from multiple tissues including respiratory tract, esophagus and colon [31, 33, 43–45] and virus entry was evidenced in gastro-intestinal tissues [46], organs of the respiratory tract and various other tissues [40]. Here, ACE2 is linked to cancer.