Among a variety of stimuli, TPA, as a tumor promoter, has been reported to induce MMP-9 expression by upregulating transcription factors, such as activator protein-1 (AP-1), signal transducer and activator of transcription-3 (STAT3), and nuclear factor kappa B (NF-κB) [14, 15]. This evidence concerns the gene STAT3 and neoplasm.