Some studies have found a decrease in mRNAs of ubiquitin ligases such as UBE3B [54] and FBXW7 [55], while other studies of ubiquitin ligase proteins found decreases in the amounts of UBE3B, FBXL21, and MDM2 [54,56] in the dorsolateral prefrontal cortex of subjects with schizophrenia. This evidence concerns the gene UBE3B and schizophrenia.