To identify risk factor genes that interact with DISC1 in synaptogenesis, we set up a genetic crossing (Supplementary Fig. S2) between the DISC1OE flies (hereafter DISC1OE represents the overexpression of DISC1 under tubP-GAL4 driver) and the fly mutants of diverse schizophrenia risk genes (Supplementary Table S1). Here, LGALS4 is linked to schizophrenia.