IMP4 (IMP U3 small nucleolar ribonucleoprotein 4) is a conserved nucleolar protein essential for early ribosomal RNA processing and ribosome biogenesis. IMP4 functions as a component of the 60-80S U3 small nucleolar ribonucleoprotein (snoRNP) complex and forms a stable hetero-trimeric complex with Imp3 and Mpp10 proteins 1. This complex is recruited to the nucleolus in a Sas10-dependent manner and serves as a core component of the ribosomal small subunit (SSU) processome, the initial precursor of eukaryotic ribosomal subunits 2. IMP4 is required for the early cleavage steps during pre-18S ribosomal RNA processing and participates in coordinated RNA folding, modifications, and processing. Beyond its canonical ribosomal function, IMP4 has emerged as a cancer-associated factor with pathological significance. IMP4 is upregulated in lung adenocarcinoma tissues and cells, where it promotes cell proliferation, migration, invasion, and glycolysis through ERK pathway activation 3. IMP4 silencing significantly suppresses these malignant phenotypes and inhibits tumor growth in vivo 3. IMP4 also functions downstream of DDX10 in lung cancer proliferation, suggesting a DDX10/IMP4 axis relevant to lung cancer pathogenesis 4. Additionally, IMP4 was identified as a hub gene in colorectal cancer transcriptional networks 5, indicating broader cancer relevance. These findings position IMP4 as both an essential ribosome biogenesis factor and an emerging oncogenic target with potential diagnostic and therapeutic applications.