CD274 and head and neck squamous cell carcinoma: EREG expression was correlated with immunoinhibitors (Supplementary Fig. 1c), of which the greatest correlations included CD274 (r = 0.115, P = 0.008 55), LGALS9 (Spearman: r = −0.429, P < 2.2e-16), TGFB1 (r = 0.363, P = 3.26e-18), and VTCN1 (r = −0.313, P = 3.39e-13) in HNSCC (Supplementary Fig. 1d).