ALTER TABLE gene_db_xref ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;
ALTER TABLE gene_exons ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;
ALTER TABLE gene_introns ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;
ALTER TABLE gene_locus_tag ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;
ALTER TABLE gene_names ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;
ALTER TABLE gene_note ADD FOREIGN KEY (id) REFERENCES gene(id) ON DELETE CASCADE;