Gene ontology analysis identifies cell proliferation pathways in the senescence signature. The DEGs shared between radiation- and p21-induced senescent cells were subjected to GO enrichment analysis, then summarized and visualized as a scatter plot using the REVIGO Web server. GO terms related to cellular process are represented by circles and are plotted according to semantic similarities to other GO terms (adjoining circles are most closely related). Circle size is proportional to the frequency of the GO term, while color indicates the log10 p value (red higher, blue lower). GO terms with a log10 p value of −7 or less for cellular process are labeled.