Based on the finding that vemurafenib-resistant cells secreted higher amounts of CD147/basigin and MMP-2 than drug-sensitive parental cells, a pilot study was carried out to investigate whether increased levels of these two proteins could be also detected in the plasma of melanoma patients developing secondary resistance to vemurafenib or vemurafenib plus cobimetinb therapy. The gene discussed is MMP2; the disease is melanoma.