Histological analysis of lungs from the mice revealed that the A549 cells produced a large number of lung nodules and metastatic tumor burden in control mice, whereas both events were markedly decreased in the mice injected with cells lacking REEP5, or REEP5 and REEP6 (Fig. 8E–G), suggesting that REEP5 and REEP6 might influence lung cancer cell metastasis. This evidence concerns the gene REEP5 and neoplasm.