And the signal transduction pathway will continue the process of cell growth, cell division and cell proliferation. So we see that one way by which a signal transduction pathway may malfunction is if a gene encoding for a protein that is part of that pathway is actually mutated. For instance, the rat gene that codes for the Ras protein in the EGF pathway is the most commonly mutated gene that leads to tumor growth of epithelial and epidermal cells. So a mutation in the gene might produce a Raspotee that is incapable of Atpa's activity, which basically means it cannot turn itself off after actually being activated. So this is essentially the off position and this is the on position. And so if we have a mutation that destroys the Atpa's activity of this structure, it will always remain on and always go on to activate Rap proteins which will contain these processes that essentially lead to self growth and division.