The role of the VDR is further supported by studies on single-nucleotide polymorphisms (SNPs), which show that certain SNPs in VDR genes (e.g., ApaI, BglI, and TaqI), associated with reduced efficacy of vitamin D supplementation, have been linked to autoimmune diseases, including IBD [20,21,22]. The gene discussed is VDR; the disease is autoimmune disease.