RAG1 and RAG2 expression in BCP-ALL.

The 39 BCP-ALLs included 9 MLL-AF4, 11 E2A-PBX1(1 sIg⁺ and 10 cIgμ⁺), 7 BCR-ABL(5 cIgμ⁺), 1 cIgμ⁺TEL-AML, 3 sIg⁺ (not from the present series), 10 cIgμ⁺, and 6 cIgμ⁻, FT-negative cases, including 6 infant ALLs. TCRG rearrangement was seen in 12 of 39 cases.