LIM Proteins have been demonstrated to play key roles in pattern formation during embryonic development, cell lineage determination, and cancer differentiation. These proteins are characterized by their conserved LIM domain, which functions as a specific protein-binding site. Recently, two new members of the LIM protein family, PRICKLE1 and PRICKLE2, were characterized in silico and demonstrated to be human orthologues of the Drosophila prickle proteins. We report on an additional member of this protein family, overexpressed breast tumor protein (OEBT). The corresponding gene was mapped to human chromosome 6p22.31. Orthologues in mouse and rat with 72 and 54% identities on a protein level were identified and the corresponding genes were mapped to mouse chromosome 17 and rat chromosome 9. The protein displays two LIM domains, as well as a PET domain, and was predicted to be localized in the nucleus. Expression of human OEBT was analyzed in silico, and the corresponding RNA was annotated to be highly expressed in a broad range of tissues. ESTs from several malignant tissue differentiations point towards a possible role of OEBT in cancer differentiation.