Beta-blocker drugs serve a key role in the treatment of heart failure, preventing bombardment of the heart by catecholamines — substances like epinephrine and norepinephrine — which overexcite and stress the heart. But not all HF patients respond to beta-blockers, for reasons that are unclear. Now, researchers show that dysfunction of beta-adrenergic receptor 3 and consequent decreases in a critical cardioprotective phospholipid may be to blame.