CD4 and neoplasm: Tumor-infiltrated CD4+Treg has been shown to inhibit the anti-tumor immunity of γδ T cells in HCC through the secretion of TGFβ and IL-10.541 Additionally, tumor-derived TGFβ can induce the differentiation of immunosuppressive CD39+ γδTreg cells in colorectal cancer (CRC).314 Circulating neutrophils542–544 and MDSCs545 in the TME can also restrain the anti-tumor response of γδ T cells.546 Therefore, fully deciphering the immune landscape of TME and elaborating the interactions between immunosuppressive cell populations and γδ T cells ensure further understanding of γδ T cell functions in TME.