Taken together, we suggest that the suppressed frequency of the Th1 (IFN-γ+CD4+) subset and the elevated Treg (Foxp3+CD4+) subset in IBC patients may represent a factor that contributes to the aggressive behavior of IBC, based on the fact that Th1 subset are typically the effector cells that mediate the main anti-cancer response [11, 35], whereas the elevated proportion of the Treg (Foxp3+CD4+) subset suppresses the anti-cancer immune response developing immune tolerance of cancer cells, and thus promote progression and aggressiveness of the cancer [36]. This evidence concerns the gene CD4 and cancer.