A recent study showed that spontaneous and immunotherapy-induced anti-tumor responses require the activity of tumor-antigen-specific CD4+ T cells, even in tumors that do not express major histocompatibility complex (MHC) class II molecules, which may be relevant with our finding that the higher level of CD4+ T cells was beneficial in RT responders of rectal cancer prognostics. The gene discussed is CD4; the disease is neoplasm.