The RUNX1T1 (Runt-related transcription factor 1; translocated to, 1) antibody is a key tool for studying the RUNX1T1 protein, also known as ETO (Eight-Twenty-One) or MTG8. RUNX1T1 is a transcriptional corepressor that belongs to the myeloid translocation gene family and plays a critical role in hematopoiesis and leukemogenesis. It is frequently involved in chromosomal translocations, most notably the t(8;21)(q22;q22) translocation, which fuses RUNX1T1 with the RUNX1 gene. This fusion, RUNX1-RUNX1T1. is a hallmark of acute myeloid leukemia (AML), particularly the M2 subtype (AML-M2), where it disrupts normal hematopoietic differentiation and promotes leukemic transformation. Antibodies targeting RUNX1T1 are widely used in research and diagnostics to detect the presence of the fusion protein, aiding in AML subtyping, prognosis, and minimal residual disease monitoring. These antibodies are employed in techniques such as Western blotting, immunohistochemistry (IHC), and immunofluorescence (IF) to study protein expression, localization, and interactions with other regulators like histone deacetylases (HDACs) and nuclear receptor corepressors (N-CoR). Additionally, RUNX1T1 antibodies contribute to understanding its role in transcriptional repression, chromatin remodeling, and its interplay with signaling pathways in both normal and malignant cells. Their specificity and reliability make them essential for elucidating mechanisms of leukemogenesis and exploring targeted therapies.