PD 174265 is a potent and selective inhibitor of the Na⁺/Ca²⁺ exchanger (NCX1), particularly the cardiac isoform. It is primarily used in research settings to study calcium homeostasis and ion transport in cardiac, neuronal, and other excitable cells. By blocking NCX activity, it helps investigate mechanisms underlying ischemia-reperfusion injury, cardiac arrhythmias, heart failure, and neurodegenerative conditions. Researchers employ it in preclinical studies to explore potential therapeutic applications for cardiovascular and neurological disorders, aiding in the identification of novel drug targets and evaluation of cardioprotective or neuroprotective strategies.