P4HA3 and head and neck squamous cell carcinoma: Because of the overexpression of P4HA3 in cancers, we analyzed the copy number amplification variation of the P4HA3 DNA fragment, and found a positive correlation between the copy number amplification variation and P4HA3 expression among various of cancers, especially in UCEC, HNSCC, LUAD, OV, KIRP, ESCA, SKCM and THYM (Fig 2C) (FDR < 0.05).