CXCR4 and neoplasm: The MnIOMCP displays reasonable T1-/T2-weighted MR contrast abilities (r1 = 13.1 mM−1⋅s−1, r2 = 46.6 mM−1⋅s−1 and r2/r1 = 3.56), good photothermal conversion efficiency (η = 28.8%), strong tumor-targeting ability (∼15.9% ID g−1 at 1 h after intravenous injection with a dose of 10 mg [Mn + Fe] kg−1) and clear inhibition of CXCR4-positive tumor growth.