Some selenoproteins are linked to the risk of cancer, as glutathione peroxidases (GPxs) (a family of antioxidant enzymes), including GPx2 (gastrointestinal) which has an antiapoptotic function in colon crypts contributing to mucosal integrity [25], and additionally, which reduces peroxide in gut [26, 27], thioredoxin reductases (TrxRs), especially TrxR1 (cytoplasmic/nuclear) which takes part in the control of transcription factors, proliferation and apoptosis of cells [28], and selenoprotein S (SEPS1) with its anti-inflammatory properties [29]. Here, PRDX5 is linked to cancer.