CTSB and colon carcinoma: On the one hand, TAMs facilitate invasive tumor potential by expression of Cathepsin B and S and matrix-degrading enzyme MMP-9 in gastric and pancreatic tumors, and on the other hand, in colon carcinoma TAMs at the invasive front have an anti-tumor role via expression of CD80 and CD86 (T cell activating costimulatory signals) (21).