Figure 3 shows the genotype combination of SNPs in CRHR1 (Figure 3a), DNAH11 (Figure 3b) and the most significant interaction in other three independent loci (TMEM175 at 4p16.3, SNCA at 4q22.1 and NSF at 17q21.31), highlighting frequency differences in cases and controls for different genotype combinations underlying the significant association with PD. The gene discussed is CRHR1; the disease is Parkinson disease.