The function of Ensembl gene identifier ENSG00000141696 (P3H4, prolyl 3-hydroxylase family member 4 (inactive)) is as follows. Part of a complex composed of PLOD1, P3H3 and P3H4 that catalyzes hydroxylation of lysine residues in collagen alpha chains and is required for normal assembly and cross-linking of collagen fibrils. Required for normal bone density and normal skin stability via its role in hydroxylation of lysine residues in collagen alpha chains and in collagen fibril assembly. .