These endogenous antigens are then processed and presented to CD8+ T and CD4+ T cells via MHC I and MHC II molecules, respectively, to induce adaptive cellular immunity (via activation of CD8+ T cells followed by their differentiation to CTLs) as well as humoral immunity (by activating the CD4+ T cells); this direct transfection of DNA into APCs, which mainly takes the form of intradermal delivery, is a momentous pathway for DNA-based cancer vaccines [292]. The gene discussed is CD8A; the disease is cancer.