PARD3 and papilloma: In the basal layers of Par3-knockout epidermal tissues as well as Par3-deficient keratoacanthomas, abnormally high levels of phosphorylated active CRaf were observed in a distinct vesicular pattern, which was moderately detected at cell–cell contacts of the suprabasal layers in wild-type epidermal tissue and only very weakly present in wild-type papilloma tissue (90).