Adipose tissue is largely comprised of adipocytes but also contains preadipocytes, endothelial cells, and infiltrating immune cells, including NK cells, T cells, and macrophages. Adipocytes are highly responsive to many hormones and growth factors that utilize the JAK/STAT pathway. The receptors for these ligands are indicated in the diagram. Infiltrating immune cells also produce cytokines which likely act in a paracrine fashion to induce JAK/STAT signaling in adipocytes. Adipocytes also have important endocrine properties and four JAK/STAT activating hormones have been shown to be produced from adipocytes.