In head and neck SCC, a high immunoscore (that is, the density of CD8+ T cells within the tumor center versus the invasive margin) has been associated with lower levels of Tregs, and increased PD-L1 and MHC type I expression in tumor cells [62], suggesting its potential to identify a subset of tumors with increased sensitivity to anti-PD-1/PD-L1 therapy. Here, PDCD1 is linked to neoplasm.