Since the linker of this compound did not significantly interact with ATX, it was decided to modify this part first, finally obtaining compound 42 (IC50 = 1.23/2.18 nM, FS-3/bis-pNPP), which showed strong anticancer effects in liver cancer and melanoma cell lines (EC50 = 7.90 and 1.30 nM) in cell experiments. This evidence concerns the gene ENPP2 and melanoma.