LH3 is ubiquitously expressed in various organs, including the heart, and it catalyzes the hydroxylation of lysyl residues of collagens and plays an important role in collagen cross-linking and deposition.28, 29, 30 Compound heterozygous variants or homozygous variants in PLOD3 of humans results in a connective tissue disorder.29 Here, PLOD3 is linked to connective tissue disorder.