CTSL and colorectal cancer: Single-cell transcriptome analyses of colon mucosae of normal, colorectal adenoma (CRA), and colorectal cancer (CRC) patients have shown increased expression of SARS-CoV2 entry-related genes such as ACE2, CD147 (Basigin), TMPRSS2, Cathepsin B (CATB), Cathepsin L (CATL), and Furin.