Although recent animal model studies indicated that cathepsin B or cathepsin S expressed by TAM play an important role in tumor progression[10,11], and we also found cathepsin B upregulated in TAM, we failed to demonstrate any correlation between cathepsin B in TAM and stage, lymph nodal metastasis, pleural invasion or differentiation in NSCLC. Here, CTSB is linked to non-small cell lung carcinoma.