For example, antibodies, peptides, or antibody parts coupling with ligands that have a major expression in tumor cells (e.g., EGFR, HER2/neu, αvβ3 integrin, uPAR, and prostate-specific membrane antigen), if linked to IONPs, provide targeted collection and retention of the IONPs in tumor tissues, resulting in T2 contrast for the detection of tumors by MRI [145]. Here, ERBB2 is linked to neoplasm.