1) MnSOD protein levels were lowered due to decreased synthesis or increased degradation, 2) the activity of MnSOD was reduced although MnSOD protein levels were unaltered. Hyperthermia can drive the ubiquitination of myeloid cell leukemia-1 (Mcl-1), and induce Mcl-1 degradation [49]. Whether hyperthermia could induce MnSOD, which could then subsequently promote ubiquitination of proteins and their degradation remains to be further studied.