CCR5 and Rett syndrome: We note again here that several autism mouse models including MECP2-duplication, neuroligin-3, 15q duplication, PTEN, CNTNAP2, and CCR5 have enhanced motor learning and plasticity (Etherton et al., 2011; Piochon et al., 2014; Rothwell et al., 2014; Frank et al., 2018), while several other mouse models including Rett syndrome, fragile X, and Angelman (15q deletion), have impaired motor learning and plasticity (Li et al., 2002; Asaka et al., 2006; Van Woerden et al., 2007; Kondo et al., 2008; Padmashri et al., 2013).