Some studies have isolated and identified breast CSCs through tumor ball culture, identified the changes in protein expression in CSCs compared with non-CSCs using LC–MS/MS, and identified a group of differential genes (PTMA, S100A4, TNXRD1, COX-1, COX-2, KRT14, and FTH1), representing possible molecular targets [121]. Here, S100A4 is linked to neoplasm.