CASP3 and neoplasm: Apoptosis of tumor cells can be induced by the activation of the PARP‐bcl‐2‐caspase 3 pathway, which also is related to mitochondria activity.36, 37, 38 Different urological cancers present different sensitivity and related cytotoxicity by niclosamide and B17 derivative via PARP‐bcl‐2 signal pathway in this study.