Actin-binding protein. Plays a role in the activation of T-cells (By similarity). Monomer. Expressed in macrophage precursors as they migrate from the midline to the yolksac during somatogenesis. Prior to blood circulation, continues to be expressed in maturing macrophage precursors in the yolksac and in those that have migrated to the mesenchyme of the head. At 28 hours post-fertilization (hpf), also expressed in the caudal part of the axial vein and the surrounding mesenchyme.