It has also shown to be a key player in head and neck SCC (HNSCC), where it can stimulate the expression of programmed death-ligand 1 (PD-L1), a ligand for PD-1 that is primarily expressed on activated T/B cells, monocytes, and a small percentage of thymocytes [30]. The gene discussed is CD274; the disease is head and neck squamous cell carcinoma.