Since the microarray analysis and real-time PCR indicated that ARHGEF7/β-PIX gene was highly down-regulated after combined treatment with rosiglitazone and AS601245, we analysed the expression of β-PIX protein in CaCo-2 cells, and in the other cell lines of colon cancer previously examined in this study: HT29 and SW480 cells. The gene discussed is ARHGEF7; the disease is colonic neoplasm.