XBP1 and acute lymphoblastic leukemia: Furthermore, the identification of the long-sought XBP1 mRNA splicing ligase opens new avenues in the treatment of a growing number of diseases associated with elevated levels of XBP1s expression such as multiple myeloma (Nakamura et al, 2006; Carrasco et al, 2007; Chapman et al, 2011), triple-negative breast cancer (Chen et al, 2014), pre-B-cell acute lymphoblastic leukemia (ALL) (Kharabi Masouleh et al, 2014) and B-cell chronic lymphocytic leukemia (CLL) (Tang et al, 2014).