SELENOS and cancer: Se, through selenoproteins, has antioxidant roles, influences immune activity, and its levels are inversely correlated with cancer risk [1] and inflammatory bowel disease (IBD) [2]–[4] In the case of IBD, red blood cell glutathione peroxidase activity [5], a Se-dependent activity and mRNA levels of Sepp1 [6], a selenoprotein, are reduced.