NPR1 and acute lymphoblastic leukemia: Interestingly, prior work observed that NPR1 was upregulated in B-lineage ALL, with no added chromosomal abnormalities compared to three other main subtypes of B-lineage ALL [33], while a separate study found NPR1 to be upregulated in mixed-lineage leukemia gene rearrangement (MLL-R) ALL [34].