PD98059 is widely used in biomedical research to inhibit the MEK/ERK signaling pathway, which plays a key role in cell proliferation, differentiation, and survival. It is commonly applied in studies involving cancer, where researchers use it to suppress ERK activation and examine the effects on tumor cell growth and apoptosis. The compound is also utilized in neuroscience research to investigate the role of the ERK pathway in synaptic plasticity, learning, and memory. Additionally, PD98059 helps in understanding cellular responses to growth factors and stress signals by selectively blocking MEK1 activation. Its application enables scientists to dissect signaling cascades and assess potential therapeutic targets in various disease models.