Spectrum of somatic mutations in STAT3 and TET2. (A) Lollipop plots indicate the frequency (y-axis) and placement within the amino acid sequence (x-axis) of detected mutations in STAT3 and TET2 proteins. (B-D) TET2 promoter methylation–specific polymerase chain reaction assay. Representative negative and positive patient sample results are indicated (B), and all gels are provided in supplemental Figure 4. (C) TET2 promoter methylation within mutational subgroups. (Fisher’s exact test, TET2 WT vs TET2 Mutant [Mut] [all samples], P = .0002; WT vs TET2 Mut, P = .0022). (D) TET2 promoter methylation of all TET2 Mut samples divided into those with ≥1 mutation. Fisher’s exact test, not significant, P = .3024). (E) Representative Sanger sequencing from isolated CD94⁺ and CD94^– fractions showing that TET2 mutations are exclusively detected in the C94⁺ NK fraction. Co-Mut, comutation.