As Fig. 3a shows, high level of c-Met and TrkB were found coexpressed in human HCC cell lines HepG2, HCC-LM3, MHCC97H, MHCC97L, and human lung carcinoma cell lines A549 cells, only TrkB expression is present in human HCC cell line SMMC-7721 and human neuroblastoma cell line SK-N-SH cells. This evidence concerns the gene NTRK2 and lung carcinoma.