PLOD2 and oropharynx squamous cell carcinoma: One of our earlier studies of oropharyngeal squamous cell carcinomas (SCCs) revealed the elevation of procollagen-lysine, i.e., 2-oxoglutarate 5-dioxygenase 2 (PLOD2), which is a secretory enzyme like LOXes that is well known to catalyze the lysyl-hydroxylation of collagen attributed to its maturation; the increased level of the protein is associated with metastasis via the recognition of integrin β-1 and the hydroxylation of it as a novel substrate to lead to the stabilization of integrin β-1 on the cell surface (29).