VCAN and breast cancer: Then we utilized a syngeneic orthotopic model of spontaneous breast cancer metastasis to test whether the exogenous expression of the versican G3 fragment in a mammary carcinoma 66cl4 cell line (a cell line that normally metastasizes to the lung but not to bone) was sufficient not only to promote local tumor growth but also to enhance metastasis to bone from the mammary fat pad.