Thus, while CD27+IFNG+ γδ T cells have been associated with active anticancer immune responses in a variety of preclinical and clinical oncological settings, including patients with MHC-negative colorectal cancer treated with immune checkpoint inhibitors (de Vries et al, 2023), CD27-IL-17+ γδ T cells have consistently been linked with accelerated tumor progression and resistance to therapy, especially (but not exclusively) in breast cancer (Coffelt et al, 2015; Petroni et al, 2025). Here, CD27 is linked to breast cancer.