Slit proteins are ligands at the Roundabout (Robo) receptors and act as guidance cues in axonal migration/navigation during neural development, at the ventral midline of the neural tube. Slit1 and Slit2 are essential for midline guidance in the forebrain by acting as repulsive signals preventing inappropriate midline crossing by axons projecting from the olfactory bulb. A number of cleavage products are reported in the literature for Slit2 protiens (following alternate splicing). The C-terminal cleavage proteins are more diffusible than the larger N-terminal protein that is more tightly cell associated. Slit2 protein is expressed in fetal lung and kidney, and adult spinal cord. Weak expression in adult adrenal gland, thyroid, trachea.