TET2 mutations in human mastocytosis patient cohort. (A) The TET2 gene with conserved regions shaded in gray. Mutations sequenced in patient samples are indicated by triangles (▵). Mutations that were found in combination with at least 1 other TET2 mutation are indicated by a closed triangle (▴). (B) Correlation analysis for mutation and aggressive disease in 74 patients diagnosed with mastocytosis as defined by WHO criteria and enrolled in a prospective national multicenter study 2005-2011.