JAK1 and acute lymphoblastic leukemia: Although this genetic translocation is rare in T-ALL patients, TCRβ-PIM1+ T-ALL patients and T-ALL subgroups (HOXA, TLX, and LYL1+ (Lymphoblastic leukemia derived sequence 1)) that have JAK/STAT activating abnormalities (JAK1, JAK2, JAK3, IL7R, STAT5A/B, PTPN2 (protein tyrosine phosphatase non-receptor type 2), and/or NUP214-ABL1 (Nucleoporin Nup214-ABL1)) all lead to very high levels of Pim-1 gene expression [105, 108].