 Nanotechnology has become increasingly important in today's society, with its applications ranging from medicine to electronics. However, there is growing concern about the potential risks associated with exposure to certain nanomaterials. Transition metal oxide nanoparticles, which are commonly used in industrial and biomedical applications, can cause toxic effects when ingested or exposed to living organisms. This paper reviews the current research on the toxicity of these oxides, focusing on their ability to induce oxidative stress, disrupt calcium homeostasis, and trigger inflammation and other cellular signaling pathways. By better understanding how these particles interact with cells, it may be possible to develop safer designs for nanomaterials. This article was authored by Robert S. Aronstam, Qi Heng Wu, and Yu Wern Huang.