In breast cancer and melanoma cells, fasting could induce SUMO modification of REV1 (a p53-binding protein and DNA polymerase) by the SUMO2 and/or SUMO3-dependent ways, consequently relieving the suppressive effect of REV1 on p53, which inhibited cancer cells by transcriptionally promoting expression of the pro-apoptotic genes [151]. The gene discussed is TP53; the disease is breast carcinoma.