γδ T cells are equipped with multiple stimulatory receptors, including the TCR, toll-like receptors (TLR) [29, 30], natural killer group 2D (NKG2D), DNAX accessory molecule-1 (DNAM-1), and natural cytotoxicity receptors (NCR) [10, 13, 31], which could potentially recognize viral components directly, or ligands produced by cells in response to viral infection. The gene discussed is CD226; the disease is viral infectious disease.