used X-ray to treat breast cancer MDA- MB-231 cell line, and eight differential proteins were identified by MS as the following: Heat shock protein 70 (HSP70), Inosine Monophosphate Dehydrogenase 2 (IMPDH2), Eukaryotic Translation Initiation Factor 4H (EIF4H), Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), Vimentin (VIM), Tubulin Alpha 1b (TUBA1B), Tubulin Alpha 8 (TUBA8) and GRP78 (64). This evidence concerns the gene IMPDH2 and breast cancer.