 For instance, in gastrointestinal cancers, nine miRNAs have been identified as epigenetically altered and effective in down regulating DNA repair enzymes.The effects of miRNA dysregulation of gene expression also seem to be important in neuropsychiatric disorders, such as schizophrenia, bipolar disorder, major depression, Parkinson's disease, Alzheimer's disease and autism spectrum disorders.Exogenous dsRNA is detected and bound by an effector protein, known as RDE-4 in "C. elegans" and R2D2 in "Drosophila", that stimulates dicer activity.