PLOD2 and head and neck squamous cell carcinoma: Moreover, a positive correlation between the expression of HIF1A-AS2 and a hypoxia signature (BNIP3, F3, LOX, TNF, TH, SLC2A1, PGK1, NDRG1, GAL, BNIP3L, ANG, P4HA1, ADM, AK3, PDK1, ERO1L, ALDOC, PLOD2, P4HA2, and MXI1; ref. 28) or HIF1A, which encodes the key hypoxic factor HIF1α, was observed in the TCGA-HNSCC database (Fig. 1E).