SREBP1 (sterol-regulatory-element-binding protein 2) is a basic-helix-loop-helix-leucine zipper (bHLH-ZIP) transcription factor. It regulates sterol and cholesterol homeostasis by controlling enzymes involved in cholesterol synthesis and uptake, e.g. HMG-CoA. The SREBP1 antibody was used in fundamental studies to dissect SREBP1 domains and downstream signaling (1).