May be involved in retinal laminar formation. Promotes epithelial to mesenchymal transition. Ubiquitously expressed, with highest levels in the retina. Up-regulated in mammary epithelial cells and hepatocytes undergoing epithelial to mesenchymal transition (at protein level). Expressed at 15.5 dpc in the nonsensory epithelium of the inner ear and at lower levels in the vestibule of the inner ear, the brain and hair follicles. Expressed in the ganglion cell layer of the retina and in the ciliary body at 15.5 dpc. At later stages, retinal expression becomes restricted to the ganglion cell layer. By TGF-beta in epithelial cells. Belongs to the FAM3 family.