Furthermore, we found that six genomic loci were mapped to a single gene (GTDC1 in genomic locus 5, NDUFAF2 in genomic locus 10, IFNGR1 in genomic locus 13, NSMCE2 in genomic locus 20, BLID in genomic locus 23, and CEBPB in genomic locus 34), implying that associations between these loci and oral ulcers were likely attributed to these genes. Here, NDUFAF2 is linked to Oral ulcer.