Protoporphyrin IX is widely used in medical and biological research due to its role in heme biosynthesis. It serves as a precursor in the synthesis of heme, which is essential for the formation of hemoglobin, myoglobin, and cytochromes. In photodynamic therapy (PDT), Protoporphyrin IX is utilized as a photosensitizer to target and destroy cancer cells. When exposed to specific wavelengths of light, it generates reactive oxygen species that induce cell death, making it effective in treating certain types of skin cancers and other malignancies. Additionally, it is employed in diagnostic applications, such as fluorescence imaging, to detect tumors and monitor treatment efficacy. Its ability to accumulate in rapidly dividing cells makes it a valuable tool in both therapeutic and diagnostic fields.