EIF4EBP1 and cardiac hypertrophy: Investigation of signaling components known to promote cardiac hypertrophy revealed increased phosphorylation of ERK, mTOR, and 4-EBP1 in CBK hearts (relative to littermate controls; Figure 1C); prior studies indicate that increased phosphorylation of these proteins are independent of absolute protein expression (McGinnis et al., 2017; Latimer et al., 2021).