The presence of cancer seems to increase the level of MMP8 in circulation and depending on the cancer, high plasma MMP8 levels might be beneficial (e.g., breast cancer [73]), but in some cancers (colorectal [32,74,75], hepatocellular [82] and melanoma [83]) high serum MMP8 levels correlate with poor prognosis. The gene discussed is MMP8; the disease is melanoma.