POMC and autoimmune disease: It is interesting to note that while different stressor types, e.g. head trauma (Ott et al. 1987), stroke (Kang et al. 2008), autoimmune diseases (Hu et al. 1993) and psychological stress (Connor & Leonard 1998), ultimately activate the HPA axis via a convergence at the hypothalamus to precipitate the CRH–ACTH–glucocorticoid cascade, there is surprisingly little overlap in the sets of genes within the brain that are induced/repressed by severe immunological stress compared with mild psychological stressors such as restraint stress (Reyes et al. 2003).