Thus, while γδ T cells isolated from peripheral blood are cytotoxic to oral tumor cells in vitro [17] and γδ T cells, as estimated by TRDC, TRGC1, and TRGC2 expression in bulk RNA-seq data, were associated with improved prognosis in HNSCC [18], Bas et al. found an increased fraction of peripheral blood γδ T cells in patients with HNSCC relative to healthy controls, as well as higher fractions in patients with recurrent disease [19]. Here, TRDC is linked to head and neck squamous cell carcinoma.