BMP4 and cardiac hypertrophy: Interestingly, the level of BMP4, a member of the bone morphogenetic protein family and a mediator of cardiac hypertrophy [93, 94], was elevated in the 5.5CG (consistent with the increased IVS-d and IVS-s values in the 5.5CG) but also in the 5.5CR, which did not feature cardiac hypertrophy.