Tyrphostin 51 is primarily used in research settings as a potent inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase. Its application is significant in studying cellular signaling pathways, particularly those involved in cell proliferation and survival. Researchers utilize this compound to investigate the role of EGFR in cancer development, as blocking this receptor can help understand its contribution to tumor growth and progression. Additionally, Tyrphostin 51 is employed in experimental studies to explore potential therapeutic strategies for EGFR-driven cancers, providing insights into targeted cancer treatments. Its use extends to biochemical assays where it helps elucidate the mechanisms of tyrosine kinase activity and its inhibition.