Furthermore, TGFβ1 is required for the differentiation of naive CD4+ T cells into pro-inflammatory interleukin-17-producing T helper cells (Th17 cells), and TGFβ1 transgenic mice exhibit marked epidermal hyperplasia, accompanied by inflammatory cell infiltration and neovascularization, mimicking the characteristics of human psoriasis [26]. The gene discussed is IL17A; the disease is psoriasis.