CALR mutations.CALR mutations determined using (A) sequencing, (B) product sizing analysis, and (C) HRM curve analysis in peripheral blood granulocytes and in BFU-E from patient 1. The homozygous BFU-E was tested twice, showing 100% and 83% allele burden. In the later experiment, the WT peak was probably due to contaminating monocytes from the media. WT, wild-type.