In humans, autosomal dominant mutations in RHBDF2 cause tylosis (Blaydon et al., 2012; Saarinen et al., 2012), a form of focal nonepidermolytic palmoplantar keratoderma (PPK) that manifests on the skin of the palms and soles (Stevens et al., 1996). This evidence concerns the gene RHBDF2 and Non-epidermolytic palmoplantar keratoderma.