Evolution is a fascinating process of adaptation, the human kallikrein (KLK) cluster, has key roles in tooth enamel maturation and skin desquamation. Previous experiments have found that inactivation of these genes causes enamel malformations in humans and mice. The present study has found that the genetic sources of dental traits commonly found in East Asians, including upper central incisor shoveling, enamel extensions of the first maxillary molar, and 4-cusped second mandibular molars,can be traced to the human kallikrein cluster (KLK). In addition to these findings in another study it has been found that”one of these variants( of the Kallikrein cluster) was already associated by other authors to reduce protection against early childhood caries.”