Based on studies in mice, expression of the ROBO3.1 isoform from the ROBO3 gene is directly stimulated by LHX2 and possibly LHX9. LHX2/9-mediated regulation of ROBO3.1 levels is involved in midline crossing by commissural relay neurons of the dorsal spinal cord (Wilson et al. 2008). ROBO3.1 levels, however, seem to be unaffected by LHX2 in thalamocortical neurons (Marcos-Mondejar et al. 2012).