ERP44 and head and neck squamous cell carcinoma: The univariate Cox analysis identified 14 key UPR-associated genes that affected HNSCC prognosis (ADGRG1, ALDOA, ERP44, GAK, GARS1, GHITM, MYH11, PFKM, PKD1, RDH11, TJP3, TPM3, TPT1, and VDAC1).