CCN2 and breast cancer: One potential explanation for these differences stems from the fact that we analyzed expression of CCN family members in breast cancer cells that had formed bone metastases and were explanted back into culture (Ouellet et al. 2011); whereas, CCN1/CCN3 and CCN2/CCN3 ratios in the MDA-MB-231 model were determined in unselected parental breast cancer cells that had not formed bone metastases (Ohgawara et al. 2011).