LUM and lung carcinoma: For studying the mechanisms and signal regulation of organ‐specific metastasis of lung cancer, our laboratory screened and established an organ‐specific metastatic lung cancer cell model from the parent lung cancer cell line L9981‐Luc, including L9981‐BrM, L9981‐LuM, L9981‐BoM, L9981‐LnM, which are only able metastasized to brain, lung, spinal column and mediastinal lymph nodes.9 The nm23‐H1 gene is a well‐known suppressor of tumor metastasis.