IL11 and cardiac hypertrophy: Previous studies in human and non-human primates have shown an association between IL11 administration and heart failure symptoms, myocardial hypertrophy, and elevation in natriuretic peptides.5,47 These associations combined with our data mechanistic data strongly question the ongoing use of rhIL11, and its further development, in patients with thrombocytopenia while identifying novel toxic effects of IL11 in the CM compartment of the heart.