For example, some genes such as ZNF134, ARHGAP26, CACNA1D, DBH, EMP1, IFI27, PDE6D, PRG3, SLC14A1, SOD2, TGFB1, THY-1, TRIM24, VAMP4, VAMP8 and ZFAND1 may improve PD’s diagnosis [47,64,65,66,67,68,69,70,71]. The gene discussed is CACNA1D; the disease is Parkinson disease.