Similar to the expression of ACE2, TMPRSS2 was not only high-expressed in respiratory (lungs) and digestive system (stomach, transverse-colon, pancreas, small intestine, esophagus -mucosa, and liver), but also up-regulated in urinary system (kidney-medulla and cortex, and bladder) and other glandular tissues (prostate, thyroid and mammary tissue), perhaps contributing to one explanation for non-respiratory symptoms in COVID-19 patients. The gene discussed is ACE2; the disease is COVID-19.