CALR-mutant MPN patients are characterized by a gene signature associated with activated JAK2 signaling. (A) Mutational status of JAK2, CALR, and MPL mutational status as well as clinical MPN diagnosis in 290 MPN patients. An individual column represents each patient. (B) GSEA showing enrichment of JAK2 shRNA signature in MPN patients with CALR mutations relative to normal subjects. (C) Heatmap representation of the 433 significantly differentially expressed genes (413 genes upregulated and 20 downregulated; FDR <0.01 and FC >2) in granulocytes from CALR-mutant MPN patients relative to normal subjects (21 MPN patients and 11 normal subjects). A red-blue color scale depicts normalized gene expression levels (red: high; blue: low). (D) GSEA showing significant enrichment of CALR-mutant MPN signature in MPN patients with homozygous JAK2V617F mutations relative to normal subjects.