JAK2 and Chronic Eosinophilic Leukemia, Not Otherwise Specified: Patient 7 (P7) M/73Y was a chronic eosinophilic leukaemia (CEL) patient who was detected to have a PCM1::JAK2 fusion transcript that showed a breakpoint in PCM1 exon 29 and JAK2 exon 11 (NM_006197.3:r.-422_4827::NM_004972.3:r.1327_*1392) (Fig. 7a).