A series of STAT3 inhibitors was developed and their anti-proliferative activity against four cancer cells investigated.180 Among them, compound 110 (Fig. 108) was the most potent with IC50 = 1.43 ± 0.30, 1.89 ± 0.42, 2.88 ± 0.69, and 3.33 ± 0.23 μM against the MDA-MB-231, HCT-116, HepG2, and MCF-7 cancer cell lines, respectively. The gene discussed is STAT3; the disease is cancer.