Cyclotherapy relies on a two-step combination approach: A) Low-level cytostatic p53 activation, which will reversibly arrest healthy cells with wild-type p53 in G1/G2 phases of the cell cycle, while leaving cancer cells with mutant/deleted p53 cycling normally and B) Use of a chemotherapeutic that targets either S or M phase cells, which will specifically target the cycling cancer cells but not the arrested healthy cells12, 13, 15, 16. The gene discussed is TP53; the disease is cancer.