MLLT11 (transcription factor 7 cofactor) is a TCF7 cofactor 1 that regulates lymphoid development by directing hematopoietic progenitors toward T cell fate 2. Beyond hematopoiesis, MLLT11 plays critical roles in neuronal migration, as loss of Mllt11 impairs cerebellar granule cell migration and reduces cerebellar size through dysregulation of non-muscle myosin IIB 3. In cancer pathology, MLLT11 is frequently dysregulated. Its knockdown inhibits breast cancer cell migration and invasion via PI3K/AKT pathway suppression while promoting apoptosis 4. In endometrial cancer, MLLT11 forms a complex with TRIL that activates PI3K/AKT/mTOR signaling, promoting tumor progression 5. In endometriosis, reduced MLLT11 expression in ectopic stroma correlates with altered cell adhesion and apoptosis resistance 6. MLLT11 is also implicated in hematologic malignancies; upregulation associates with poor AML prognosis 7, and 1q gains containing MLLT11 occur in Burkitt lymphoma 8. However, KMT2A::MLLT11 fusions in pediatric AML are classified as intermediate-risk rather than favorable 9. These findings identify MLLT11 as a multifunctional regulator with tissue-specific roles in development and disease.