Phospho-Cofilin (Ser3) Antibody detects endogenous levels of Cofilin only when phosphorylated at Serine 3. cofilin 1 a cytoskeletal protein that controls actin depolymerization. Has a 5-10-fold higher affinity for ATP-actin monomers than cofilin-1. May promote filament assembly rather than disassembly. Two alternatively spliced variants are described.