We then investigated the subcellular localization of FHL2 by immunogold labeling in cardiac myofibres on ultrathin sections of ventricular tissue obtained from of a human donor, a patient with aortic stenosis, two HCM patients with a MYBPC3 mutation, and from WT and Hom-KI mice (Fig. 1f–k). Here, FHL2 is linked to aortic stenosis.