Cell proliferation measured using CellTiter-Glo assay in 293A and HMCES KO cells without or with transfection with viruses encoding CtIP (F) shRNAs. Each experiment was repeated three independent times done in triplicates each time. Data was represented as mean±s.e.m. Student's t-test was used to calculate statistical significance (***, p<0.001; ****, p<0.0001). 