Similar to Nestin-Cre;Tbr2F/F mice (Hodge et al., 2013), Lmx1a-Cre;Tbr2F/F mice exhibited aberrant accumulation of Reelin+ CR cells at the FDJ, associated with a reduced HF length (Figure 4—figure supplement 1D–F), supporting the conclusion that Tbr2 acts intrinsically in the CR cell lineage to regulate migration of CR cells and HF/DG morphogenesis. The gene discussed is RELN; the disease is hydrops fetalis.