Increased MMP2 secretion via IL-23 signaling may be mediated through signal transducer and activator of transcription 3 (STAT3) [62] as STAT3 activity regulates MMP2 expression and human brain metastatic melanoma cells and tissue biopsies show increased STAT3 activity as compared to cutaneous melanoma cells and extracranial lesions [63]. The gene discussed is STAT3; the disease is metastatic melanoma.