SELENOS and cancer: In these studies, selenium has a sufficient geographic scientific basis as an adjuvant treatment of cancer [6], reducing the toxicity of chemotherapeutic drugs, increasing the subject’s tolerance to chemotherapeutic drugs, etc. However, these studies have been conducted to detect cancer-related target genes in various dosage forms of selenium only, and all of them ignored the detection of selenoprotein gene expression and the uncovered mechanisms that selenoproteins play the biological functions.