Metastatic status is known for 259 of these patients enabling us to investigate a correlation between metastasis and ABCB1 expression.20 Positive ABCB1 expression was more likely to be observed in metastatic tumors (50.5%) compared to non-metastatic tumors (37.7%; P = .04; Figure 4A). The gene discussed is ABCB1; the disease is metastatic neoplasm.