FN1 and cancer: This strategy emerged as alternative due to the difficulties to target cancer cells and is based in findings that have shown certain proteins are abundantly expressed in regions surrounding tumours and at basal levels in healthy tissues.56, 57 Han et al functionalized gadofullerenes with the small peptide ZD2 (Cys‐Thr‐Val‐Arg‐Thr‐Ser‐Ala‐Asp), which has high affinity towards the extra domain‐B fibronectin (EDB‐FN), a protein abundantly expressed in the extracellular matrix of many types of aggressive human cancers (Figure 7).