Figure 1

H1339 human small cell lung cancer cells were exposed to 0.5 μg/ml cisplatin for 3 h. The cells that had survived were allowed to recover for 7 days and were again exposed to 0.5 μg/ml cisplatin. After 4 "cycles", the survival after a 5th exposure was compared to the survival of naïve cells. Pre-treated cells showed an increased survival fraction compared to naïve cell (* = P < 0.01).