MLK3 protein expression was detected in human hearts, increased in myocardium from patients with both nonischemic and hypertrophic cardiomyopathy (MLK3/GAPDH: non-ischemic: 6.26 ADU ± 0.85, n=9, hypertrophic: 6.97 ADU ± 1.42, n=8), and in hearts of mice subjected to cardiac pressure overload (n=8, +138.0%). Here, MAP3K11 is linked to hypertrophic cardiomyopathy.