PDGFRA and atypical chronic myeloid leukemia, BCR-ABL1 negative: This BCR-PDGFRA fusion was first discovered in patients with aCML with a breakpoint of t(4;22) (q12;q11), fusing either exon 7or exon 12 of BCR to exon 12 of PDGFRA [43] (Figure 1).