(A) Cisplatin dose response curves of (i) MB002, (ii) Daoy, and (iii) MIC in the absence (EV) or presence of SOX9 by Alamar blue. Cells were pre-conditioned with doxycycline to induce expression of SOX9 (or EV) prior to treatment with increasing concentrations of cisplatin. The IC50 were calculated following 5 (MB002 and MIC) or 3 days (Daoy) of treatment. Data are mean + standard deviation from 3 independent repeats, each containing 5 technical replicates. 