EBF1 and acute lymphoblastic leukemia: Philadelphia chromosome (Ph)‐like acute lymphoblastic leukemia (ALL) is a genetically and clinically heterogeneous disease characterized by various chromosomal rearrangements, sequence mutations involving kinase or cytokine receptor signaling pathway activation and a high frequency of alterations in transcription factors involved in B cell development, including IKZF1, PAX5, and EBF1.1, 2, 3