In turn, Wnt4 induces MM cells to undergo mesenchymal-to-epithelial transformation (MET) and differentiate into nephron epithelia [13]. Six2, a homeodomain transcription factor expressed in the MM, maintains MM cells in undifferentiated state, thereby allowing continued UB branching and nephron formation to proceed [16]. The gene discussed is SIX2; the disease is Miyoshi myopathy.