Alteration of ACE2 protein expression in common malignancies. By semi-quantifying ACE2 protein expression, elevated expression was found in colorectal adenocarcinoma, pancreatic adenocarcinoma (matched tissues), gastric adenocarcinoma, and papillary renal cell carcinoma (matched tissues). While reduced expression was found in matched tissues of chromophobe renal cell carcinoma, testicular seminoma, and papillary thyroid adenocarcinoma. T, tumor tissues; N, normal tissues. * < 0.05; *** < 0.01.