KIF21B and Parkinson disease: Sixteen out of the 26 genes analyzed were novel PD candidate genes involved in pathways potentially deregulated in PD such as mitochondrial metabolism and oxidative stress (AIMP2, HMOX2, IMMT, MAN2C1, RHOT2, SLC25A39, TOMM22) [27–35], vesicular trafficking, microtubule dynamics, autophagy (CHMP1A, GIPC1, HSPA8, KIF21B, KIF24, SPTBN1, TMEM175, TVP23A) [36–42] or in SNCA gene expression (ZSCAN21) (Fig. 2a) [43, 44].