Functions as a repressor of epidermal cell outgrowth and negatively regulate trichome branch formation (PubMed:18805951, PubMed:21070410). Acts as both a positive and negative regulator of cellular outgrowth. Promotes both trichome expansion and branch formation (PubMed:21070410). Coordinately with WIN1/SHN1, participates in the regulation of cuticle biosynthesis and wax accumulation in reproductive organs and trichomes. Functions in cuticle nanoridge formation in petals and stamens, and in morphogenesis of petal conical cells and trichomes (PubMed:23709630). May play a role in the regulation of cuticle formation in vegetative organs (PubMed:24169067). Expressed in trichomes, stems, carpels, petals and stamens. Overbranched trichomes.