For the most part (autism, childhood obesity, depression, bipolar disorder and schizophrenia, Alzheimer's and Parkinson's disease, and multiple sclerosis), the bacterial defence NOD signalling network was involved, while the similar Toll pathway was more restricted (Alzheimer's and Parkinson's disease and multiple sclerosis, bipolar disorder, and schizophrenia). This evidence concerns the gene TLR4 and bipolar disorder.