CRLF2 and acute lymphoblastic leukemia: Consistent with our hypothesis, global transcriptome analysis using two distinct methodologies (PCA and unsupervised hierarchical clustering of all differentially expressed genes) confirmed that naïve Eμ-Crlf2/Jak2R683G B-ALL cells (control) and those with acute or chronic knockdown of Jak2 all displayed distinct transcriptional profiles, and their respective replicates clustered identically (Fig. 5B,C).