The titers of viral particles produced from non-transduced U373-SUMO-1 and from transduced U373-SUMO-1 shUbc9 and U373-SUMO-1 NS cells after infection with HCMV at an MOI of 1 were determined and compared to those produced from infected U373-Neo and U373-Neo shUbc9 control cells. This evidence concerns the gene SUMO1 and infection.