DNMT1 and autism: Subsequently, experimental validations in Arrb2−/− mice verified the downregulation of Myh9, Dnmt1, and Brd4 on mRNA and protein levels in the hippocampus, along with protein kinase A (PKA)-induced hyperactivation of Synapsin I. These findings lay the foundation for exploring the regulatory role of Arrb2 in autism pathogenesis and its potential as a therapeutic target.