As our in vitro binding assay did not detect a direct interaction between LDB2 and EGRs, we speculate that LDB2 cooperates with the EGR family via unknown protein(s) to control expressions of numerous genes including ARC (Fig 9) and that the “LDB2‐EGR axis” may potentially underlie the etiology of subset of mental disorders. The gene discussed is ARC; the disease is mental disorder.