Andelfinger et al., 2019 reported the use of Trametinib in two infants with Noonan syndrome associated with RIT1 mutations, who suffered from severe, early-onset hypertrophic cardiomyopathy. One of the neonates had bilateral, chylous pleural effusions. They postulated that MEK inhibition might limit myocardial hypertrophy as RIT1 mutations cause RAS pathway activation (Andelfinger et al., 2019). Their theory was supported by beneficial effects in preclinical mouse models for both cardiac and extra-cardiac manifestations of RASopathies (Hernandez-Porras et al., 2014; Wu et al., 2011). The gene discussed is RIT1; the disease is hypertrophic cardiomyopathy.