NGDN (neuroguidin) is a critical component of ribosome biogenesis, functioning as part of the small subunit (SSU) processome required for 40S ribosomal subunit synthesis 1. NGDN forms a salt-stable nucleolar protein complex with AATF and NOL10, termed the ANN complex, which supports nucleolar steps of 40S ribosomal subunit biosynthesis and 18S rRNA maturation 1. The protein's UTP3/SAS10 domain is essential for complex formation 1. NGDN functions as a pre-rRNA binding protein despite lacking canonical RNA binding domains 2. The protein is part of the RNA polymerase I interactome, with its RNA binding activity dependent on active rRNA transcription 2. Disease relevance includes roles in cancer, where NGDN overexpression increases chemotherapy sensitivity in multidrug-resistant acute myeloid leukemia cells by affecting mTOR pathway activation 3. Somatic NGDN variants have been identified in growth hormone-secreting pituitary adenomas, where they affect tumor biochemical activity 4. Additionally, NGDN variants serve as prognostic indicators in osteosarcoma 5. Disruption of NGDN's interaction with its complex partners can impair ribosome biogenesis and contribute to neurodevelopmental disorders 6.