6-GIN has been shown to cause apoptosis in the cervical cancer cell line HeLa by activating the caspase-3-dependent pathway 11. In previous studies, it inhibited the metastasis of the breast cancer cell line MDA-MB-231 and caused the apoptosis of the prostate cancer cell line LNCaP 12,13. 6-GIN also inhibits the growth of several types of murine tumors such as melanomas, renal cell carcinomas, and colon carcinomas 14,15. The present study demonstrates that 6-GIN induces the apoptosis of the bladder cancer cell line 5637. Here, CASP3 is linked to melanoma.