To gain a comprehensive understanding of the roles of IL-6 signaling in cancer cell responses to genotoxic treatments, we started out by investigating changes in the levels of IL-6 and its receptor (IL-6Rα) as well as in the phosphorylation of its downstream effector STAT3 (signal transducer and activator of transcription 3) following the treatments of cancer cells with DNA-damaging agents, such as sodium arsenite (SA) [22], doxorubicin (Dox) [23], or cisplatin (CisPt) [24]. Here, STAT3 is linked to cancer.