PAX5 and acute lymphoblastic leukemia: Alterations are also detected in the transcription factors involved in B lymphocyte development and maturation, including IKAROS family zinc finger 1 (IKZF1), EBF transcription factor 1 (EBF1), ETS variant transcription factor 6 (ETV6), ETS transcription factor ERG, transcription factor 3 (TCF3), and paired box 5 (PAX5), in 86% of the cases and with a frequency very similar to what is observed in Philadelphia‐positive B‐ALL cases.7