Essential hematopoietic-specific regulator of the actin cytoskeleton (Probable). Controls lymphocyte development, activation, proliferation and homeostasis, erythrocyte membrane stability, as well as phagocytosis and migration by neutrophils and macrophages (PubMed:16417406, PubMed:17696648). Component of the WAVE2 complex which signals downstream of RAC to stimulate F-actin polymerization. Required for stabilization and/or translation of the WAVE2 complex proteins in hematopoietic cells (By similarity). Within the WAVE2 complex, enables the cortical actin network to restrain excessive degranulation and granule release by T-cells (PubMed:32647003). Required for efficient T-lymphocyte and neutrophil migration (PubMed:32647003). Exhibits complex cycles of activation and inhibition to generate waves of propagating the assembly with actin (PubMed:16417406). Also involved in mechanisms WAVE-independent to regulate myosin and actin polymerization during neutrophil chemotaxis (PubMed:17696648). In T-cells, required for proper mechanistic target of rapamycin complex 2 (mTORC2)-dependent AKT phosphorylation, cell proliferation and cytokine secretion, including that of IL2 and TNF (PubMed:32647003). In hematopoietic cells, component of the WAVE2 complex composed of ABI1, CYFIP1/SRA1, NCKAP1L/HEM1 and WASF2/WAVE2 (PubMed:16417406, PubMed:32647003). Interacts with ARHGAP4, PIK3C3/VPS34 and PPP1R12A/MYPT1 (PubMed:16417406). Interacts with mammalian target of rapamycin complex 2 (mTORC2) components, including MTOR and RICTOR (PubMed:32647003). Localizes to the leading edge of polarized neutrophils. Expressed only in cells of hematopoietic origin (PubMed:7643388, PubMed:1932118). Expressed in neutrophils (at protein level) (PubMed:16417406). Expressed in T-cells (at protein level) (PubMed:32647003). The disease is caused by variants affecting the gene represented in this entry. Belongs to the HEM-1/HEM-2 family. Truncated N-terminus.