EN2 (engrailed homeobox 2) is a homeodomain-containing transcription factor that functions as both a sequence-specific DNA-binding protein and a secreted signaling molecule 1. As a transcription factor, EN2 exhibits dual regulatory activity, functioning as both a transcriptional activator and repressor depending on cellular context, with the ability to bind RNA polymerase II cis-regulatory regions and modulate gene expression 23. EN2 demonstrates unique intercellular mobility, capable of traveling between cells and modifying transcriptional activity in recipient cells 4. During development, EN2 is strongly expressed in rhombic lip derivatives including cerebellar structures, inferior olive, and arcuate nucleus, suggesting roles in central nervous system patterning 5. In cancer contexts, EN2 acts as an oncogene, promoting tumor progression through multiple mechanisms including direct transcriptional regulation of target genes like CCL20 in colorectal cancer 2 and stabilization of NOTCH pathway signaling in head and neck squamous cell carcinoma 3. EN2's secretion into urine by prostate cancer cells, but not normal prostate tissue, makes it a promising diagnostic biomarker 1. Additionally, EN2 hypermethylation serves as a prognostic marker in colorectal cancer 6.