Rhombotin-1 is a protein encoded by the LMO1 gene.LMO1 enocdes a cysteine-rich, two LIM domain transcriptional regulator. It is mapped to an area of consistent chromosomal translocation in chromosome 11, disrupting it in T-cell leukemia, although more rarely than the related gene, LMO2 is disrupted.Boehm et al. (1988) and Greenberg et al. (1989) studied a previously identified translocation  associated with T cells in acute lymphoblastic leukemia. The translocation involves the TCR-delta gene on 14q11 and also a transcribed sequence on 11p15. They found that the gene on 11p15 is normally expressed in rhombomeres of the developing hindbrain. The gene product, designated rhombosine or rhombotin, has 155 amino acids and no homology to any previously described protein.