depots (WAT and BAT) or in the microenvironment of diverse tissues. Within the microenvironment of tissues that contains ectopic or interspersed adipose tissue or adipocytes, such as the breast, bone marrow, and the perirenal and epicardial regions, FGF21 may serve to modify adipocyte signaling that affects parenchymal cell functions through a paracrine mechanism. Within stressed adipose tissues which are predominantly adipocytes, both paracrine and autocrine mechanisms may be at play. The ultimate effect of the communication initiated by the FGF21 messenger is to elicit beneficial signals from adipocytes that aid in reduction of the effects of stress and prevention of tissue-specific damage and pathologies resulting from prolonged stress.
