By co-immunoprecipitation assay, we found that the amount of ANXA2 proteins pulled down by an antibody against ubiquitin was significantly reduced in hippocampus of CRS mice comparing to control mice, illustrating that HDAC9 can inhibit the ubiquitination-mediated degradation of ANXA2 (Fig. 4D). This evidence concerns the gene HDAC9 and congenital rubella syndrome.