In this note, we study patients whom receive radiotherapy in their cancer treatment process. While more than half of the patients undergo such treatment, our understanding of abnormal transcriptional responses to radiation remains poor. In this study, we investigate genes and biological processes associated with ionizing radiation (IR) and ultraviolet radiation (UV) exposure using a microarray dataset. Gene expression levels were modeled on a gene interaction topology downloaded from the Human Protein Reference Database (HPRD). This was performed for IR, UV, and mock datasets, separately. The difference curvature value between IR and mock graphs (also between UV and mock) for each gene was used as a metric to estimate the extent to which the gene responds to radiation. We found that in comparison of the top 200 genes identified from IR and UV graphs, about 20∼30% genes were overlapping. Through gene ontology enrichment analysis, we found that the metabolic- related biological process was highly associated with both IR and UV radiation exposure.