Tyrphostin AG 879 is a protein tyrosine kinase inhibitor with potent effects on TrkA. This product reportedly inhibits NGF-induced PLC-γ 1 phosphorylation and phosphatidylinositol-3 kinase activation. Has been shown in lab studies to disrupt Sertoli cell aggregation and stop androgen-induced cell proliferation. AG 879 also displays anti-cancer effects by inhibiting the expression of RAF-1 gene encoding MAP kinase activity necessary for human breast cancer cell proliferation. Shown to inhibit Neu (HER-2 or ERBB2) expression and reduced tumor sizes in mice leukemia cells. Tyrphostin AG 879 is an inhibitor of Flk-1.