229–231 Whole-exome sequencing identified CALR mutations in ~70% to 80% of JAK2V617F-negative ETs and primary myelofibrosis.232,233 In vivo research demonstrated that CALR mutation alone was strong enough to initiate an MPN phenotype and increased JAK-STAT signaling activity. The gene discussed is SOAT1; the disease is myeloproliferative disorder.