When we compared the number of foci with HO-1+ macrophages in GS 7–10 tumors with metastases (n = 14) to the number of GS 7–10 tumors without metastases (n = 31) at diagnosis, it was 0.48 +/- 1.0 per unit area in non-metastatic tumors and 1.1 +/- 1.2 in metastatic tumors (p = 0.05). The gene discussed is HMOX1; the disease is metastatic neoplasm.