NSC-87877 is a cell-permeable inhibitor of both SHP-1 and SHP-2 protein tyrosine phosphatases (IC₅₀ = 355 and 318 nM, respectively). It is much less effective against other protein tyrosine phosphatases and the dual-specificity phosphatase 26. Inhibits EGF-induced Erk1/2 activation in HEK293 cells and significantly reduces MDA-MB-468 cell viability/proliferation.