E2ATCF3

E2ATCF3 is a nonstandard or ambiguous symbol that sometimes appears in literature or database records as a concatenation of the E2A transcription factor (gene symbol TCF3) with itself or its related terminology. In conventional nomenclature, the protein encoded by the TCF3 gene is known as E2A, and its principal isoforms are E12 and E47. E2A functions as a basic helix-loop-helix transcription factor that is essential for early lymphoid development and other developmental processes, acting as a regulator of gene expression through DNA binding at E-box motifs and through dimerization with other transcription factors.

Two major isoforms arise from alternative splicing: E12 and E47. These isoforms differ in their activation domains and regulatory properties, contributing to distinct transcriptional programs. E2A participates in networks that control B cell lineage commitment, immunoglobulin gene rearrangement, and broader cellular differentiation programs. Its activity is modulated by interactions with cofactors, inhibitors, and post-translational modifications that influence dimer formation and DNA binding.

In clinical contexts, rearrangements involving TCF3 can produce oncogenic fusion proteins. The best-characterized examples are E2A-PBX1 in acute lymphoblastic leukemia and E2A-HLF in rarer leukemia subtypes, which disrupt normal transcriptional regulation and contribute to leukemogenesis. The term E2ATCF3 is not a standard gene symbol or widely accepted fusion name in major genomic databases, and its use is likely a typographical variant or shorthand related to E2A/TCF3 concepts. When cataloging, researchers should refer to TCF3 (E2A) and established fusion partners such as PBX1 or HLF to avoid ambiguity.