JAK2 and acute promyelocytic leukemia: However, when she was diagnosed with APL, genetic tests revealed JAK2/V617F as negative, PML/RARαV variant (23.85% mutation load), WT1-Exon1 (37.8%), WT1-Exon9 (4.1%), JAK3-Exon7 (49.3%), and RELN-Exon55 (45.8%).