To investigate the universality of Taz in the regulation of Hh signaling, we further examined the potential effect of Taz on Hh signaling in a variety of cell types and embryonic kidneys, where Taz null alleles develop polycystic kidney disease (Tian et al. 2007; Makita et al. 2008). The gene discussed is WWTR1; the disease is polycystic kidney disease.