ATM and systemic sclerosis: In a GWAS study that included 5471 SSc patients of European ancestry, HLA-DQB1 locus was associated with anticentromere antibodies (ACA), HLA-DPA1/B1 loci with anti-DNA topoisomerase I antibody (ATA), and neurogenic locus notch homolog 4 (NOTCH4) with ACA and ATA (24).