IMP3 (IMP U3 small nucleolar ribonucleoprotein 3) is a component of the U3 small nucleolar ribonucleoprotein complex required for early cleavages during pre-18S ribosomal RNA processing 1. It functions as part of the small subunit processome, which coordinates ribosome biogenesis through RNA binding, modification, and targeted degradation 2. However, IMP3 has emerged as a clinically significant oncofetal protein with dual roles. In normal physiology, IMP3 expression is largely restricted to fetal tissues, but it is aberrantly reactivated in malignant neoplasms 3. IMP3 promotes tumor cell proliferation, adhesion, and invasion through its RNA-binding capacity 3. In lung adenocarcinoma, IMP3 expression correlates with advanced TNM stage, lymph node metastasis, and poor overall survival, serving as an independent prognostic predictor 4. IMP3 also functions as a diagnostic marker in cholangiocarcinoma and bile duct adenocarcinoma, where it demonstrates strong cytoplasmic staining in malignant tissues but absent or minimal expression in benign epithelium 5. Additionally, IMP3 expression associates with tumor aggressiveness in chondrosarcoma and osteosarcoma, correlating with histological grade and metastatic potential 6. These findings establish IMP3 as a valuable biomarker for cancer diagnosis and prognosis across multiple malignancies.