CD8A and neoplasm: The strikingly different effects of VPA/HPTA on macrophage polarization demonstrated in the cell model in vitro, with and without the tumor cell medium environment, allow us to make bold speculation that in the animal model, in addition to promoting M1 polarization of macrophages to activate anti-tumor response of CD8+ T cells, VPA/HPTA may also exhibit protection against the injury of distant normal tissues induced by RT, as it is possible to mediate anti-inflammatory effects via macrophage M2 type polarization.