Background: AKAP13/AKAP-Lbc was originally identified as an oncogenic protein that associates with the GTP-binding protein Rho. AKAP13-Lbc is also a member of the A-kinase anchoring protein family that functions as a molecular scaffold for the subcellular compartmentalization of A- kinase signaling molecules. AKAP13-Lbc has been found to possess Rho-specific guanine nucleotide exchange factor (GEF) activity and is critical to mediating RhoA activation and signal transduction.