KRT5 and hyperplastic polyp: This function was clarified after the delineation of the impact of KRT5 mutations in such pathologies as Galli–Galli disease (GGD), Dowling–Degos disease (DDD), and some forms of EBS [87], as, for example, EBS with migratory circinate erythema (EBS-MCE) with c.1649delG of KRT5 and EBS with mottled pigmentation (EBS-MP) with the mutations p.Pro25Leu or p.Gly138Glu in K5 [181].