TMPRSS2 and inflammatory bowel disease: We performed in silico analysis of our colonic gene microarray dataset (99 CD, 129 UC and 50 non-IBD controls; available at Gene Expression Omnibus (http://www.ncbi.nlm.nih.gov/geo/ [accessed September 2020] accession: GSE11223 and GSE20881) [5] to demonstrate ACE2 gene expression in whole gut mucosal biopsies is significantly higher in the ileum compared with colon, with the reverse pattern seen for TMPRSS2 (Fig. 1B).