The LIM-domain-only (LMO) family of proteins function as linkers in the co-regulation of nuclear transcription by mediating protein-protein interactions. The four members of the LMO family collectively have significant roles in cell fate determination, cell growth and differentiation, and organ development. LMO2 encodes a cysteine-rich, two LIM-domain protein that is required for yolk sac erythropoiesis. The LMO2 protein has a central and crucial role in hematopoietic development and is highly conserved. The LMO2 transcription start site is located approximately 25 kb downstream from the 11p13 T-cell translocation cluster (11p13 ttc), where a number T-cell acute lymphoblastic leukemia-specific translocations occur. Alternative splicing results in multiple transcript variants encoding different isoforms. LMO2 has a particular function in normal and lymphatic endothelial cells involving the regulation of angiogenesis and lymphangiogenesis. Immunohistochemical studies have also demonstrated expression of LMO2 in both normal germinal center B-cells and germinal center-derived B-cell lymphomas, including follicular lymphoma and diffuse large B-cell lymphoma. The use of anti-LMO2 is valuable as a tool in the identification of lymphomas of B-cell origin.