Laboratory mice have become the premier animal model for most human and domestic animal diseases, and they have long been the model of choice for studying mammalian genetics, especially since the advent of genetic engineering. Many remarkable discoveries have been made through intense study of these wonderful small mammals, and undoubtably many more will be made. It is no surprise that one mouse model for alopecia areata (AA) has been found possibly many more will be, some of which exhibit rare phenotypes found in subpopulations of humans with the disease, such as nail deformities, thyroid disease, inflammatory bowel disease, and autoimmune polyendocrine syndrome type 1. Intense investigation by many groups into the first model, the adult onset form of AA (using the C3H/HeJ inbred strain), found similarities as well as differences with commonly held ideas concerning human AA. Regardless of some of the controversies, much insight has been gained from studying these and other rodent and domestic animal models which has opened up new ideas and discussions of AA and its treatment.