The allosteric inhibitor of MEK1/2 (PD098059) was one of the first MEK (the MAPK kinase that phosphorylates ERK1/2) inhibitors to be tested in these mice, delaying the development of left ventricular dilatation and improving function (Muchir et al., 2009). The gene discussed is MAP2K1; the disease is Left ventricular dilatation.