The TCF3-PBX1 fusion gene does not cause the RT alterations observed in TCF3-PBX1–positive cells. (A) Downregulation of the TCF3-PBX1 fusion protein with siRNA oligonucleotides in the Kasumi2 cell line. (B) Downregulation of TCF3-PBX1 fusion protein with siRNA oligonucleotides in the RCH cell line. (C-D) Genome-wide correlation matrices of Kasumi2 and RCH cells before and after downregulation of TCF3-PBX1 fusion protein. (E-F) Exemplary RT profiles at 2 distinct chromosomal regions confirms that the RT program is preserved after downregulation of TCF3-PBX1 fusion protein in Kasumi2 (E) and RCH (F) cell lines. (G) Overexpression of a TCF3-PBX1 complementary DNA (cDNA) in the normal B-cell line (GM12878). (H) Genome-wide correlation matrix of normal B cells with and without overexpression of the TCF3-PBX1 cDNA. (I) Exemplary RT profiles confirm that the RT program is preserved after overexpression of TCF3-PBX1 fusion protein in normal B cells. RQ, relative quantification.