DKK1 and neoplasm: Next, to further understand the local effects of DKK1 in the TME, we isolated tdT+ CAFs from primary tumors in αSMA-Dkk1cKO-tdT and αSMA-Dkk1WT-tdT mice and co-injected them with PyMT tumor cells (1:1 ratio) into the MFP of naïve WT recipient mice.