- Transgenic mice with cardiac-specific over-expression of MLK7 have increased mortality when exposed to chronic beta-adrenergic stimulation. Christe, M., Jin, N., Wang, X., Gould, K.E., Iversen, P.W., Yu, X., Lorenz, J.N., Kadambi, V., Zuckerman, S.H., Bloem, L.J. J. Mol. Cell. Cardiol. (2004)