TCF3 and precursor B-cell acute lymphoblastic leukemia: RNA-seq efficiently detects genetic rearrangements identified by traditional tests, covering both common fusions (ETV6-RUNX1, TCF3-PBX1, BCR-ABL1) and novel genetic rearrangements potentially influencing B-ALL pathogenesis, while sensitivity to a low tumor burden or lowly expressed fusions (like KMT2A rearrangements) and rearrangements in promoter/enhancer regions (e.g., IGH rearrangements) is limited [31].