BMP4 and cardiac hypertrophy: Assuming that, BMP4 indeed plays a pivotal role in mediating the pathological cardiac hypertrophy (Sun et al., 2013), no significant changes in BMP4 expression in the hearts of the Tgαq*44 mice and the WT mice after the 8 weeks of spontaneous physical activity found in our study, clearly suggests that this kind of physical exercise does not increase the risk of development of BMP4‐mediated cardiac hypertrophy.