Interleukin (IL)-6 drives many of the cancer ‘hallmarks’ through downstream activation of the Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling pathway [32], we wanted to find whether STAT3 plays a role in IL-6-induced MMP2 and MMP9 expression. This evidence concerns the gene MMP9 and cancer.