Because human liver cancer cell line Huh7 has endogenous expression of ACE2, whereas the ACE2 expression could not be detected in HEK293T and HeLa cells (SI Appendix, Fig. S2), we examined the stability of ACE2 in Huh7 cell under the conditions of knockdown (KD), knockout (KO), and overexpression (OE) of SNX27. This evidence concerns the gene ACE2 and liver cancer.