Moreover, Shen et al. have shown that the 2-(6-Hydroxyhexylthio)-5,8-dimethoxy-1,4-naphthoquinone is able to induce the apoptosis in human lung cancer A549 cells via same MAPK/STAT3 pathway, demonstrating the important role of naphthoquinones as a promising anticancer candidate targeting various types of tumors [47]. Here, STAT3 is linked to lung cancer.