HDAC1 and hydrops fetalis: When HF cells were infected with HCMV for 24 h and co-IP assays were performed, IE1 was coimmunoprecipitated with STAT1, STAT2, HDAC1, HDAC2, and PML (Fig. 6A), whereas immunoprecipitation with control IgG did not coprecipitate any of these proteins in the control (Fig. 6A).