Unique features of MSA that all contribute to its anti-cancer activities include its capacity to induce ROS accumulation, to inhibit the phosphorylation of AKT, ERK and p53, and to facilitate proteolytic activation of caspase-8 and -320, 24–26.Moreover, metabolism of MSA generates the precursor of methylselenol, which is an active Se form and reported to induce the apoptosis of cancer cells27. This evidence concerns the gene CASP8 and cancer.