Furthermore, in the kidney, loss of PC (through the genetic deletion of Thm1, which encodes tetratricopeptide repeat protein 21B/TCC21B, a component of the IFT-A complex) leads to the formation of renal cysts, though deletion of the same gene in the liver does not automatically lead to hepatic cyst formation, indicating that different tissues are variously sensitive to cilia loss (21-23). The gene discussed is TTC21B; the disease is cystic kidney disease.