In numerous studies using various cancer cell lines, curcumin was shown to inhibit cellular proliferation by down-regulating the JAK-STAT3 pathway in chronic lymphocytic leukemia B cells [146], human multiple myeloma U266 cells [147], pancreatic cancer cells [148,149], ovarian and endometrial cancer cells [150,151], melanoma cells [152,153], cutaneous T-lymphoma cells [87], malignant gliomas [154,155], myeloid-derived suppressor cells [101], lung cancer [156,157], and hepatocellular carcinoma [158]. Here, STAT3 is linked to cancer.