DDR2 and neoplasm: (C) Number of total lung metastases in MMTV-PyMT (WT) (n = 18 mice) or FSP1cre; Ddr2fl/fl; MMTV-PyMT (Ddr2-/-; FSP1cre) (n = 10 mice) mice at termination (@20 weeks or when a single tumor reached 2 cm).