 FE-304 nanosimes are a promising class of nanoparticles with potential applications in cancer treatment. They exhibit peroxidase-like activity which can generate reactive oxygen species, ROS, leading to the destruction of tumour cells. However, inconsistencies in their cytotoxicity have been reported, suggesting that surface modifications may be necessary to optimise their therapeutic efficacy. This article was authored by Guo Hintang, Zhu Yangyi, Zhu Wenliu, and others.