IGF1 and adenocarcinoma: Administration of IGF-1 ligand to these mice reversed the reduction in bothtumor growth and metastases.39in addition, in Noble rats (prostate carcinoma model), increased IGF-1 levelsresulting from exposure to high levels of sex hormones led to progression from benignprostatic growth to adenocarcinoma of the prostate40 IGF-1 signaling appears to prevent apoptosis byup-regulating the expression of MDM2.