Heat-induced activation of the immune system is mediated by heat shock proteins (HSPs); they increase antigen presentation and maturation of dendritic cells, stimulate the phagocytic function of macrophages, induce the release of tumor neoantigens from tumor cells, favor the proliferation and cytotoxicity of CD8+ T and NK cells, promote the activation and proliferation of B lymphocytes and inhibit T-regulatory (Treg) cells. This evidence concerns the gene CD8A and neoplasm.