MIXL1 (Mix paired-like homeobox) encodes a paired-type homeobox transcription factor that plays essential roles in early embryonic development and cellular differentiation. During embryogenesis, MIXL1 is transiently expressed in primitive streak-like cells and is required for proper mesendoderm morphogenesis and endoderm formation 12. The gene is transcriptionally regulated by TGF-β signaling through SMAD and FoxH1 binding sites in its promoter, with Nodal identified as a key embryonic regulator 3. MIXL1 expression correlates with enhanced definitive endoderm differentiation efficiency in human induced pluripotent stem cells, and enforced expression can improve endoderm differentiation propensity 4. In hematopoietic development, MIXL1 is expressed in B- and T-cell progenitors and enables isolation of primitive hematopoietic precursors 2. However, MIXL1 also has pathological significance in cancer. High MIXL1 expression is frequently observed in aggressive lymphomas, where it correlates with proliferation index and may contribute to lymphomagenesis 5. In acute myelogenous leukemia, MIXL1 functions as a proto-oncogene by transcriptionally activating c-REL and downstream survival genes BCL2L1 and BCL2A2, and MIXL1-expressing AML cells show sensitivity to BMP receptor inhibitors 6.