Schema of the experimental design used for transducing CNR cells on d5 and d6. A total of 6 experiments were performed for these studies. In 4, the retroviral vector LNL6 was used on d1 and the vector G1Na on d5 and d6. In the other 2 experiments, the sequence was reversed. The schema presented here depicts the sequence of experimental steps used when cells were transduced with LNL6 on d1 and with G1Na on d5 and d6.