Treatment of neuroblastoma cell lines with CDX0239-PBD led to significantly higher levels of caspase activity as compared to treatment with free PBD at concentrations as low as 1 pM in high surface ALK-expressing NB-1, 10 pM in moderate surface ALK-expressing NB-SD, and this effect was not observed in low surface ALK-expressing SK-N-AS (Fig. 5D). The gene discussed is ALK; the disease is neuroblastoma.