NTN4 and Parkinson disease: Comparative analysis revealed that PLBD2, LPO, PCYOX1L, RSPO2, SDC1, RBM3, PBX1, CDH8, NTN1, SUSD1, SEMA3G, ANK1, SLIT1, NTN4, LRRC3B, OLFM3, DLK1, and KIAA0319 were expressed at low levels in PD samples, while AKR1C1 and RELN were highly expressed (Figure 3B).