CASP8 and cancer: In addition, MSA, especially at concentrations of 5 and 15 μM, was capable of activating caspase-8 in THP-1 cancer cells and, conversely, inhibiting them in healthy PBMS cells, which is consistent with previously obtained data that selenium compounds in a dose-dependent manner were able to induce apoptosis in cancer cells while protecting normal tissues [56,57,58].