The article by McCarthy and Weissleder reviews the recent advancements in multifunctional magnetic nanoparticles for targeted imaging and therapy. These nanoparticles, particularly iron oxide-based, have become crucial tools in diagnosing and treating diseases such as cancer, atherosclerosis, and diabetes. The review highlights the development of targeted nanoparticles using affinity ligands, including peptides, antibodies, and small molecules, which enhance their specificity and efficacy. The synthesis and functionalization of these nanoparticles are discussed, emphasizing the importance of coatings to ensure stability and biocompatibility. The article also explores the use of multifunctional nanoparticles for multimodal imaging, combining imaging and therapeutic agents, and their potential in theranostic applications. Examples of targeted imaging in atherosclerosis and cancer are provided, demonstrating the ability of these nanoparticles to accurately target specific cell types and molecular targets. The future perspectives section outlines the potential of multifunctional nanoparticles in creating theranostic agents for the targeted diagnosis and treatment of diseases.The article by McCarthy and Weissleder reviews the recent advancements in multifunctional magnetic nanoparticles for targeted imaging and therapy. These nanoparticles, particularly iron oxide-based, have become crucial tools in diagnosing and treating diseases such as cancer, atherosclerosis, and diabetes. The review highlights the development of targeted nanoparticles using affinity ligands, including peptides, antibodies, and small molecules, which enhance their specificity and efficacy. The synthesis and functionalization of these nanoparticles are discussed, emphasizing the importance of coatings to ensure stability and biocompatibility. The article also explores the use of multifunctional nanoparticles for multimodal imaging, combining imaging and therapeutic agents, and their potential in theranostic applications. Examples of targeted imaging in atherosclerosis and cancer are provided, demonstrating the ability of these nanoparticles to accurately target specific cell types and molecular targets. The future perspectives section outlines the potential of multifunctional nanoparticles in creating theranostic agents for the targeted diagnosis and treatment of diseases.