We saw that ARID5B and PHF2 expression were positively correlated in ALL and that ARID5BlowPHF2low expression is associated with leukemic cell proliferation (high bone marrow blasts and splenomegaly, low HGB and PLT), as well as a poor prognosis (high percentage of Ik6+, ≥4 weeks to reach CR upon treatment, and CD33+) in B-ALL patients. This evidence concerns the gene PHF2 and Splenomegaly.