HHaA is a human pseudogene believed to be responsible for fur-like body hair. In humans the gene has become deactivated making it a pseudogene, however there is variation in the degree of body hair among human beings and occasional examples have been found of people where the gene is active leading to very thick body hair as a result.
- Winter, H.; Langbein, L.; Krawczak, M.; Cooper, D. N.; Jave-Suarez, L. F.; Rogers, M. A.; Praetzel, S.; Heidt, P. J.; Schweizer, J. (2001). "Human type I hair keratin pseudogene phihHaA has functional orthologs in the chimpanzee and gorilla: Evidence for recent inactivation of the human gene after the Pan-Homo divergence". Human Genetics. 108 (1): 37–42. PMID 11214905. doi:10.1007/s004390000439.