GATA2 expression in CRISPR/Cas9-modified HL-60 cultured cells. (A) Grand means from several independent dPCR experiments. The P values from t tests are shown in each panel when significant. The TBP and HPRT1 genes were used as reference control genes. The GATA2:TBP signal ratio for the wt enhancer is 1.067 ± 0.030 and for the A-to-T mutant is 1.093 ± 0.0209, and the GATA2:HPRT1 signal ratio for wt is 0.3065 ± 0.0215 and for the A-to-T mutant is 0.3353 ± 0.0173. (B) HL-60 dPCR mutant:wt cell GATA2 expression ratio normalized to HPRT1 expression. Expression increased in the mutant cell line through 4 days of continuous growth, with the average mutant:wt ratio of 1.269 ± 0.220. (C) GATA2 expression measured with rs2335052 allele-specific dPCR probes and normalized with TBP. The total expression is the sum of the 2 rs2335052 probes; wt 0.4623 ± 0.01968, mutant 0.5964 ± 0.02892 when normalized to TBP (t test; P ≤ .0001). (D) Ratio of the reference and alternate sequence alleles at rs2335052 in wt (1.007 ± 0.04127) and A-to-T enhancer mutant cell lines (1.408 ± 0.04411).