CRLF2 and precursor B-cell acute lymphoblastic leukemia: Moreover, CRLF2, which is frequently overexpressed in Ph-like B-ALL (Jain et al., 2017; Iacobucci et al., 2021), was expressed at lower levels in samples #1 and #2 than sample #4, Ph+, and TN B-ALL (Figure 2B, Supplementary Table S2).