Activation of P2X7 and P2Y1 receptors with high concentrations of extracellular ATP triggered colon cancer cell apoptosis [26], whereas low concentrations of ATP or UTP stimulated cell proliferation through P2Y1 and a downstream pathway that involves PKC, Src kinases and cell surface metalloproteases [26, 27]. This evidence concerns the gene P2RY1 and malignant colon neoplasm.