IGF1 and neoplasm: Given that the IGF1 pathway is a recognized stimulator of cell growth and plays an important role in neoplasia [18], and that IGF1 bioavailability is increased upon MMP11 overexpression [12], we investigated whether the IGF1 signaling pathway is exacerbated in tumor extracts from 6-week-old PyMTTg; MMP11Tg mice.