Based on limited published evidence, KRTAP20-2 encodes a keratin-associated protein (KRTAP) essential for hair shaft structure. In the hair cortex, KRTAP20-2 is embedded within the interfilamentary matrix where it cross-links with hair keratin through extensive disulfide bonding via abundant cysteine residues, contributing to hair rigidity and resistance 1. The protein is expressed in hair follicles and localized to the cytosol. Genetic variation in KRTAP20-2 associates with cashmere fiber traits and wool production characteristics, suggesting potential as a genetic marker for fiber quality improvement 12.