ACE2 and cancer: ACE2 had a protective effect in five types of cancer: brain (OS: total number = 74, HR = 0.44, Cox P = 0.003507), eye (distant metastasis-free survival: total number = 63, HR = 0.00, Cox P = 0.033962), lung (OS: total number = 129, HR = 0.70, Cox P = 0.009280), ovarian (OS: total number = 278, HR = 0.63, Cox P = 0.048512), and renal (OS: total number = 59, HR = 0.17, Cox P = 0.021041).