STX4 and Parkinson disease: The remaining 17/27 candidate genes – ZBTB7B, MUC1, CLK2, DAP3, SCAMP3, ADAM15, RUSC1, SHC1, ARHGEF2, KAT8, STX4, IGF2BP3, PPM1L, DCUN1D1, NSF, BAG3 and TOM1L2 – are to be regarded as novel PD candidate genes.