MMP2 and head and neck squamous cell carcinoma: Specific to targeting HNSCC, Tsien et al. [130,131] have developed a peptide simultaneously targeting RGD-binding integrins using cRGDfC and a MMP-2 activatable peptide, building on their observation that the MMPs are also overexpresssd in HNSCC [132] and interact with αvβ3.