Our results have demonstrated that FLLL32 is an effective STAT3 inhibitor to inhibit STAT3 phophorlation, STAT3 DNA binding activity, STAT3 downstream target gene expression and induce apoptosis in human cancer cells from four independent cancer types such as multiple myeloma, glioblastoma, colorectal and liver cancers. This evidence concerns the gene STAT3 and AL amyloidosis.