Briefly, HeLa cells were infected with the CRISPR-Cas9 library at 0.2 multiplicity of infection (MOI) to control only one transgene copy number in most of the cells and selected by puromycin, and then re-infected with the pAd-DsRed-IRES-EGFP-Cdc25A adenovirus. The gene discussed is CDC25A; the disease is infection.