To further study the probable role of GSG2 in the progression of breast cancer, we analyzed the difference of GSG2 expression in 1,056 breast cancer samples classified according to tumor stages, and found that GSG2 is significantly up-regulated in stage II compared with stage I (Figure 3a), suggesting that the increase of GSG2 expression may play an important role in the development from stage I breast cancer to stage II. The gene discussed is HASPIN; the disease is breast cancer.