Some genes fall into multiple categories, e.g. IRS2 is associated not only with diabetes and receptor mediated signal transduction for specific extracellular cytokines, but also with epilepsy (70), aspects of schizophrenia (43), Alzheimer's disease (71–73), retinal degeneration (74), hippocampal synaptic plasticity (75), long term potentiation of hippocampal synaptic transmission (76), ataxia (77), cardiac failure (78), kidney development (79), renal disease (80), breast cancer (81,82), rhabdomyosarcoma (83) and, in conjunction with JAK23N-hCR, hematopoesis (84,85). The gene discussed is IRS2; the disease is schizophrenia.