Some indications are that both autosomal and recessive polycystic kidney disease cyst formation is tied to cilia-mediated signaling that is irregular. Further, the polycystin-1 and polycystin-2 proteins appear to be involved in both autosomal and recessive polycystic kidney disease due to defects in both proteins.[11] Both proteins have communication with calcium channel proteins this causes reduction in resting (intracellular) calcium and endoplasmic reticulum storage of calcium.[12] The disease is characterized by a ‘second hit’ phenomenon, in which a mutated dominant allele is inherited from a parent, with cyst formation occurring only after the normal, wild-type gene sustains a second genetic ‘hit’, resulting in renal tubular cyst formation and disease progression.[13] Specifically, PKD is thought to result from defects in the primary cilium, an immotile, hair-like cellular organelle present on the surface of most cells in the body, anchored in the cell body by the basal body.[13] In the kidney, primary cilia have been found to be present on most cells of the nephron, projecting from the apical surface of the renal epithelium into the tubule lumen. In response to fluid flow over the renal epithelium, the primary cilium is bent, resulting in a flow-induced increase in intracellular calcium.While it is not known how defects in the primary cilium lead to cyst development, it is thought to possibly be related to disruption of one of the many signaling pathways regulated by the primary cilium, including intracellular calcium, Hedgehog, Wnt/β-catenin, cyclic adenosine monophosphate (cAMP), or planar cell polarity (PCP).function of the primary cilium is impaired, resulting in disruption of a number of intracellular signaling cascades that produce dedifferentiation of cystic epithelium, increased cell division, increased apoptosis, and loss of resorptive capacity.[8][13]