The function of CDC42SE2 (CDC42 small effector 2, ENSG00000158985) is as follows. Probably involved in the organization of the actin cytoskeleton by acting downstream of CDC42, inducing actin filament assembly. Alters CDC42-induced cell shape changes. In activated T- cells, may play a role in CDC42-mediated F-actin accumulation at the immunological synapse. May play a role in early contractile events in phagocytosis in macrophages. {ECO:0000269|PubMed:10816584, ECO:0000269|PubMed:15840583}.