Expression of Nck1 and Nck2 in colon and breast cancer cells. Lysates (50 μg protein) from murine colonic carcinoma cells (A) and human breast cancer cells (B) were subjected to western blot analysis using anti-Nck specific antibodies (Additional file 1). CT36: rarely metastatic; CT51: intermediary; CT26: highly metastatic. MCF-10A: Normal human breast epithelial; MCF7, T47D, MDA-MB-231: invasive metastatic ductal carcinoma. For both cancer cell types, β-actin was probed as loading control.