When fat accumulates in the liver, the immune system may assault the organ. A new study from Weill Cornell Medicine researchers identifies the molecule that trips these defenses, a discovery that helps to explain the dynamics underlying liver damage that can accompany type 2 diabetes and obesity.

In a study published Aug. 19 in Science Immunology, researchers mimicked these human metabolic diseases by genetically altering mice or feeding them a high-fat, high-sugar diet. They then...