Based on limited published evidence, KRTAP22-1 encodes a keratin-associated protein (KAP) that functions in hair and wool fiber structure. In the hair cortex, KRTAP22-1 is embedded within the interfilamentous matrix, where it contributes to rigid and resistant hair shaft formation through extensive disulfide bond cross-linking with cysteine residues of hair keratins 1. The protein belongs to the high-glycine-tyrosine KAP family. In sheep, KRTAP22-1 genetic variants associate with wool traits, with variant B linked to increased wool yield and decreased fiber curvature 1. The protein localizes to the cytosol and functions as a structural matrix component essential for fiber mechanical properties.