Furthermore, we found 13 BXD lines with low expression signals for Krt4, Krt13 and Krtdap. Krt4 and Krt13 have been shown to be responsible for White sponge nevus (WSN), also known as Cannon's disease, which is an autosomal dominant skin condition in humans [45-47]. Here, KRT13 is linked to White sponge nevus.