To determine whether the wild‐type PAX5 allele is present or absent in human PAX5‐JAK2+ B‐ALL cells, we interrogated the RNA‐seq data of 8 human PAX5‐JAK2+ B‐ALL tumors to identify sequence reads spanning the unique exon junctions of the wild‐type PAX5 gene (exon 5‐exon 6) and PAX5‐JAK2 rearrangement (PAX5 exon 5‐JAK2 exon 19). The gene discussed is JAK2; the disease is acute lymphoblastic leukemia.