USP7 and acute lymphoblastic leukemia: A GWAS of 1191 children with T-ALL and 12,178 control subjects identified eight USP7 SNPs of genome-wide significance, four of which (rs61426394, rs74010349, rs59591814, and rs74010351) clustered close to the USP7 transcription start site in a region marked by the strong promoter-active histone modifications H3K4me3 and H3K27ac in two of the T-ALL cell lines analyzed.