Rac1 is a GTPase that is involved in the regulation of the cell cycle, cell-cell adhesion, motility, and differentiation. Rac1 is activated by its interaction with specific guanine nucleotide exchange factors (GEFs). NSC 23766 is a cell-permeable, reversible inhibitor of Rac1 activation by the Rac-specific GEFs TrioN and Tiam 1 (IC50 = 50 μM). It has no effect on the closely related GTPases, Cdc42 and RhoA. NSC23766 has been used to investigate the role of Rac1 in such diverse cellular functions as stem cell mobilization, epithelial cell migration, angiogenesis, leukemia cell migration and growth, and gene expression.
