PDCD1LG2 and head and neck squamous cell carcinoma: Notably, STAT3/FUT8-mediated PD-L2 glycosylation is a pivotal regulator of immune evasion and responsiveness to anti-epidermal growth factor receptor (EGFR) therapies in HNSCC, indicating PD-L2 glycosylation may be a potential strategy to enhance the therapeutic response of HNSCC patients to anti-EGFR therapies [70].