In a randomized double blind control trial of patients with Parkinson disease (PD), the effect of vitamin D3 (1200 IU/day for 12 months) to stabilize PD were only associated with the VDR FokI TT or CT but not the other SNPs examined (i.e., BsmI, Cdx2, ApaI and TaqI) [43]. The gene discussed is CDX2; the disease is Parkinson disease.