IFIT1 and head and neck squamous cell carcinoma: In contrast, IFITM3 expression in HNSCC samples was positively correlated with immunosuppressive proteins such as programmed cell death ligand 1 (PD-L1), interferon induced protein with tetratricopeptide repeats 1 (IFIT1), B7-H7, V-domain Ig suppressor of T-cell activation (VISTA), indoleamine 2,3-dioxygenase (IDO), CD68, CD163 and CD206 (244).