We assess the effect of lung adenocarcinoma cells on TAM through detecting the expression of SHP2, p- STAT1, p-STAT3, p-STAT5, p-STAT6, IL-4, IL-10, Cathepsin-L, Cathepsin-S, Cathepsin-K and Arginase-1 in each group of THP1 cells cocultured with and without A549 cells by western blot. This evidence concerns the gene CTSL and lung adenocarcinoma.