CAPG, also known as actin Regulatory Protein CAPG, is a a member of the gelsolin/villin family. Members of this family are actin-regulatory proteins. CAPG reversibly blocks the barbed ends of F-actin filaments in a Ca2+ and phosphoinositide-regulated manner, but does not sever preformed actin filaments. By capping the barbed ends of actin filaments, CAPG contributes to the control of actin-based motility in non-muscle cells. CAPG may also play an important role in macrophage function.