CD4 and neoplasm: Currently, the investigation of the roles played by various subtypes of γδ T cells in tumor development and migration represents a prominent focus in fundamental research, through molecules associated with apoptosis such as FAS/FASL pathways, BTN3A-BTN2A1 complexes, and their interactions with CD4, CD8, and NK cells have emerged as potential targets for activating Vγ9Vδ2 T cells (42, 115).