ACE2 and gastric adenocarcinoma: Some studies have found that ACE2 is aberrantly expressed in some cancers, such as lung adenocarcinoma, renal carcinoma, and stomach adenocarcinoma, and it is correlated with prognosis and immune infiltrates (Hoang et al., 2020; Kong et al., 2020; Tripathi et al., 2020; Chen L. et al., 2021; He et al., 2021).