This apoptosis of the cancer cells can be explained in two ways: either mutated p53 proteins, reactivated by treatment, induce the overexpression of NEDD9 in the G1 phase of the cell cycle, instead of the G2/M phase, and this disrupts the normal cell cycle; or the levels of NEDD9 protein increase and cross the threshold. The gene discussed is NEDD9; the disease is cancer.