IGF1 and IGF1 receptors (IGF1R) are present in the adult heart and have been shown to be essential for myocardial performance. Insulin-like growth factor 1 (IGF1) is produced in numerous tissues particularly by the liver in response to growth hormone stimulation and is an important factor in the regulation of post-natal growth and development. We have generated and characterized transgenic mice over-expressing the IGF1R. We crossed IGF1R transgenic mice with dominant negative (dn)PI3K (p110) and with constitutively active (ca)PI3K(p110) transgenic mice. Expression profiling was performed on the ventricles of IGF1R, IGF1R-caPI3K, IGF1R-dnPI3K, caPI3K, dnPI3K transgenic female mice at 3 months of age. Non-transgenic littermates were used as controls. Keywords = insulin growth factor, IGF, cardiac, hypertrophy