To confirm the effects of M2 cells-secreted CHI3L1 protein on cancer cell metastasis (cell migration, adhesion and invasion), a polyclonal anti-CHI3L1 antibody was added to the co-cultures of cancer cells and healthy human peripheral blood monocytes-derived M2 macrophages to neutralize the activity of CHI3L1. The gene discussed is CHI3L1; the disease is cancer.