CRLF2 and precursor B-cell acute lymphoblastic leukemia: Some of the most significant subtypes found in B-cell acute lymphoblastic leukemia (B-ALL) are MLL (KMT2A) rearrangements, ETV6::RUNX1 translocation, ETV6::RUNX1-like ALL, BCR::ABL1 Philadelphia chromosome ALL, Philadelphia chromosome-like ALL, ZNF384-rearranged ALL, PAX5-rearranged ALL and CRLF2-rearranged ALL [5,6,7].