The latest issue of JACC provides further in-depth examination of the framework for understanding heart failure with preserved ejection fraction (HFpEF) and guiding treatment through the lens of adipocyte biology and secreted mediators, also known as the "adipokine hypothesis," developed by Milton Packer, MD, FACC. The focus issue features perspectives from experts in HFpEF, obesity and adipokine biology, with the goal of charting a path forward. Read more. Also explore the new JACC Interactive Adipokine Tool, which allows readers to explore the molecules and understand their functional roles in HFpEF.