Human brain organoids are remarkable platforms for modeling features of human brain development and diseases. Building on methods to generate organoids to model different brain regions such as the cortex and the midbrain, researchers at the Perelman School of Medicine at the University of Pennsylvania have generated the first organoids of the arcuate nucleus (ARC), an essential structure in the hypothalamus that sends signals of hunger and feeling full. This part of the hypothalamus exhibits a tremendous amount of cell diversity, and is far more complex than previously modeled parts of the brain.