MYLK3 and heart failure: We noted, nonetheless, that 19 days after tamoxifen injection into perinatal Mylk3-KO mice, there was a heart failure with increase of the heart weight/body weight ratio, reduction of contractility with increase of both systolic and diastolic left ventricular cavity with elongation but without thinning of cardiomyocytes, and increase of fetal gene expression compared to controls.