Matched tumor and lung specimens were sectioned and staining was conducted against the V5 epitope to determine if pulmonary metastases from Cadm1 positive tumors retained expression of V5-tagged Cadm1. As shown in Figure 4A–4F, the primary tumors (Figure 4A–4B) stained positive for the V5 epitope, however, pulmonary metastases (Figure 4C–4D) from matched tumors did not stain for V5, indicating that these metastases had lost expression of the Cadm1 transgene. The gene discussed is CADM1; the disease is neoplasm.