Here, we show that qRT-PCR-based analysis of Trp-1 transcription can also be used to quantify low pulmonary metastatic burden in the Tg(Grm1)/Cyld−/− autochthonous melanoma model, extending the range of metastasis models for which qRT-PCR-based strategies can be used. The gene discussed is GRM1; the disease is melanoma.