Keratin 37 (KRT37)

The hair keratin genes range in size from 4.2 to 7.5 kb, and the genes are separated from each other by 5.5 to 18.4 kb; all are located within about 140 kb.One subcluster, group A, consists of KRTHA1, KRTHA3A, KRTHA3B, and KRTHA4, which share 89% overall amino acid identity.

A second subcluster, group B, contains KRTHA7 and KRTHA8, as well as the hair keratin pseudogene, which the authors called HAA. The functional hair keratins and hypothetical HAA hair keratin share approximately 81% overall amino acid identity. Due to an almost completely identical head domain, KRTHA7 and KRTHA8 are 92.6% identical. The third subcluster, group C, consists of the structurally less related hair keratins KRTHA2, KRTHA5, and KRTHA6, which share about 70% amino acid identity.