LMO4 is a novel member of the LIM-only (LMO) subfamily of LIM domain-containing transcription factors, so named because they are composed almost entirely of two tandem LIM domains. This subgroup of LIM proteins has 4 members: LMO-1, LMO-2, LMO-3 and LMO-4. They all play important roles in the normal mammalian development, functioning as an important regulator of cell proliferation. LMO4 is highly expressed in the epithelial compartments at locations of active epithelial-mesenchymal interactions, and can interact with some signaling pathways involved in epithelial-mesenchymal signaling. Thus the disregulation of LMO4 expression may be involved in tumorigenesis. In this paper, we will at first expound LMO4 in detail, based on which the possible mechanisms for its interaction with TGF-β signaling and the roles of this cross-talk between them in the vital process of cell will be introduced. All of those will add to our understanding of tumorigenesis and contribute to the search of new targets for the treatment of cancer.