CD200 and breast cancer: Since attenuation of the stemness of breast cancer cells may downregulate the expression of their immune checkpoints, we also determined the regulatory pathways associated with stemness and immune checkpoints, and constructed gene signatures, which represent Wnt, TGF‐β, and Hedgehog signaling‐related CD200 and CD276 expression in breast cancer stem cells, to predict the prognosis of patients with breast cancer.