Based on the results from the above mutation screening as well as the fact that PLXNA4 is known to be expressed in the brain [15] and a role for axonal guidance factors similar to PLXNA4 already postulated in PD [16], we further analyzed subcellular localization of the protein in the two cell lines but could not detect a difference (Figure 3B). The gene discussed is PLXNA4; the disease is Parkinson disease.