IGF1 and cancer: Matrix metalloproteinases (MMPs) have two opposite functions, which are promoting and inhibition of cancer.A.MMPs promote cancer growth by cleaving insulin-growth-factor-binding protein (IGF-BP), releasing IGF; through transmembrane precursor growth factors including growth factor-α (TGF-α); and by regulating extracellular matrix, indirectly increase interaction between extracellular matrix and integrins.