A schematic diagram representing natural sources and cellular targets of lathyrol in multiple human cancer cell lines. Semen Euphorbiae is a traditional Chinese medicine prepared from ripen fruits of Euphorbi lathyrus. Lathyrol is the major components of Semen Euphorbiae and Euphorbi lathyrus. Lathyrol binds with DNA binding domain of STAT3 and induces cleavage of caspase-3 in cancer cells to induce apoptosis.