WNT1 and breast cancer: In a Wnt1 subcutaneous model (mammary tumors initially isolated from Wnt1 (int-1) transgenic mice [32]), single agent E7449 treatment (100 mg/kg) did not inhibit tumor growth whereas significant antitumor activity was observed following administration of the porcupine inhibitor Wnt-C59, a potent Wnt signaling antagonist (Figure 8A).