We were sorting through scientific images recently, cataloguing and filing in a well-intentioned year-end swirl. This caught our eye: it's an islet of Langerhans that has been isolated from a human pancreas and stained to highlight the expression of insulin and glucagon, the hormones that regulate blood sugar. Beta cells, which produce the insulin needed to help lower blood sugar, show up as red. The green cells are alpha cells that express glucagon, which raises blood sugar. (The cell culture and microscopy was done by Deepika Walpita here at the Broad.)