Transduction efficiency of the HIV-based vector into cells deficient in DSB repair enzymes. (A) ATM-deficient cells and ATM-complemented cells were transduced with three different dilutions of the HIV-based vector encoding a GFP reporter. Two days postinfection, the percentage of GFP-positive cells was determined by flow cytometry. (B-D) The influence of DNA-PKcs (B), NBS1 (C) and Mre11 (D) on transduction efficiency of the HIV-based vector was investigated by the same method as (A). Error bars represent +/- SD.