For example, 5-HTT and MAOB belonged to the 2 maximally 2-frequent itemsets, which were closely related to ‘Schizophrenia,’ ‘Autistic Disorder,’ and ‘Post-Traumatic Stress Disorder.’ Additionally, 25 association rules were obtained, indicating a close associative degree among genes. The gene discussed is MAOB; the disease is post-traumatic stress disorder.