miR-211-5p/ROBO1 inhibit proliferation, invasion and migration of stomach cancer cells; down-regulate MMP2, MMP7, MMP1, P-P-38, etc. to inhibit migration and invasion of A549 (lung cancer cell line); promote generation of apoptins PARP, caspase-9 and procaspase3, and promote apoptosis of N2a (neuroblastoma Neuro-2a cells). Here, MMP2 is linked to lung cancer.