BMSCs transfected by no-load virus red fluorescent protein would be used in in vivo models to evaluate the action mechanism of TGF-α locally expressed in BC lesion in influencing the BMSCs and in promoting bone metastasis, information from which could lead to therapeutic targets by controlling TGF-α signaling in both primary lesion and the surrounding microenvironment. The gene discussed is TGFA; the disease is breast cancer.