H2BC15 and depressive symptom measurement: The gene-based analysis revealed several genome-wide significant genes associated with depression (top-ranked: HIST1H2BN, HIST1H3J, SORCS3) and BIP-I (top-ranked: CACNA1C, MAD1L1, PLEC); and BIP-II was significantly  associated with SLIT3. These genes have been reported previously for the respective GWAS37,38.