Here, we determine the level of B16.F10gp metastasis to the lungs using a triplex Q-PCR method, which detects the expression of the melanoma genes GP100 and tyrosinase-related protein 2 (TRP-2) relative to the reference gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH). The gene discussed is DCT; the disease is melanoma.