PPARγ activation also promotes the differentiation of basal bladder cancer cells to the luminal subgroup, cooperating with amplification of GATA3 and FOXA1 or activation of estrogen receptor (ER) 28, 29 and displaying downstream enrichment of CD24, ERBB3, ERBB2, FGFR3, ELF3, CDKN1A and TSC1 mutations and overexpression of E-cadherin, HER2/3, Rab-25 and Src 30, 31. The gene discussed is ERBB2; the disease is urinary bladder cancer.