Alternatively, these variants may not cause the disease themselves but may be in LD with other or unknown disease-causing variations in the regulatory region of SMAD7. For example, a novel variant mapping to the enhancer of SMAD7 was found to be in LD with the colorectal cancer risk variant rs4939827 (intron 3) identified in a GWAS study; this variant proved to be functional in transcription factor binding and gene expression [9], [11]. The gene discussed is SMAD7; the disease is colorectal cancer.