Consistent with a possible role of NF1 mutations in HCM, conditional knock-out mice lacking the murine ortholog, Nf1, in myocardium, were shown to have normal embryonic cardiovascular development but marked cardiac hypertrophy, progressive cardiomyopathy, and fibrosis in the adult, together with hyperactivation of Ras and downstream pathways [45]. Here, NF1 is linked to cardiac hypertrophy.