MMP9 and neoplasm: The number of TAM infiltration and MMP‐9 expression is positively relevant to tumor vascular density, and TAM increases MMP‐9 expression to promote angiogenesis in HCC, involved in type 1 insulin‐like growth factor (IGF‐1) signaling via phosphatidylinositol3‐kinase (PI3‐K) and mitogen‐activated protein kinase (MAPK) pathways.24