To address how the known function of ARSB, which is to remove the 4-sulfate group from N-acetylgalactosamine 4-sulfate residues at the non-reducing end of chondroitin 4-sulfate (C4S) or dermatan sulfate, could lead to enhanced apoptosis in melanoma, the effects of rhARSB on C4S and associated parameters were determined in the B16F10 melanomas and A375 cells. This evidence concerns the gene ARSB and melanoma.