XAF1 and gastric cancer: Interestingly, some of the genes identified in our methylation study are included in the CellAge signature of the HAGR repository, for instance, TP63, shown to induce senescence in mouse- and human-derived fibroblasts [57]; XAF1, found over-expressed in IRR-SIPS and Dox-SIPS pulmonary microvascular endothelial cells [58]; SLC13A3, accelerating RS in human diploid cells and renal tubular cells [59]; or EZH2, the deficiency of which has been shown to lead human gastric cancer cells to senescence [60].