IGF1R and cardiac hypertrophy: Similarly, miR-378 has also been shown to play a role in the repression of cardiac hypertrophy by targeting Mapk1, Igf1r (insulin-like growth factor 1 receptor), Grb2 (growth factor receptor-bound protein 2) and Ksr1 (kinase suppressor of ras 1), components of the MAP kinase pathway, in rat cardiomyocytes [32].