Mvt1 tumor growth and metastasis development are more rapid in MKR+/+ mice compared to controls. A total 100,000 Mvt1 cells were injected into the left inguinal mammary fat pad of control and MKR+/+ mice (8 to 10 per group). (A) Mammary tumor volume (mm3) measured by calipers. (B) Terminal weights of Mvt1-induced mammary tumors. (C) Numbers of pulmonary macrometastases in control and MKR+/+ mice. (D) H & E staining of control and MKR+/+ lungs, arrows indicate metastases. Error bars represent SEM *, P ≤ 0.05.