In the human colon cancer cell line Caco2, endocannabinoids failed to show any proliferative effect via CB1 receptors in differentiated cells [90]; however, in undifferentiated cells, cannabinoids were strongly antiproliferative via CB1 and this was not because of alterations in the levels of CB1 receptors. The gene discussed is CNR1; the disease is malignant colon neoplasm.