Hypermethylation of CpG islands has been revealed in transcription factor binding sites in the CNR1 promoter of colorectal cancer cell lines and tissue samples examined [108]; it was further found that inhibition of DNA methyltransferase profoundly elevates the CNR1 transcription, suggesting a crucial contributing role of CNR1 promoter hypermethylation in downregulating CB1R expression in colorectal cancer. The gene discussed is CNR1; the disease is colorectal cancer.