In order to define the complex genetics and physiology of adipose tissue, investigators have generated a large number of transgenic and knockout mouse models.10 and 11 The number of transgenic animal models is continuing to increase. To date, more than 500 animal models involving the study of adipose tissue have been generated. Since it is impossible to cover all of these models in this review, a very subjective selection of animal models relevant to the study of adipose tissue is presented. The author is aware that numerous valuable transgenic animal models are not mentioned here; a more complete overview of current animal models created to investigate adipose tissue can be found in other recently published reviews.10 and 11 The impact of the central nervous system on the control of food intake and adipose tissue development, as well as specific aspects of the endocrine response and signal transduction in adipocytes, including adrenergic receptors, GTP-binding proteins, protein kinases, growth hormone and IGF-1 signalling, the role of oestrogens, glucocorticoids and other hormones, have been reviewed elsewhere and are therefore not discussed here.