NOL11 (nucleolar protein 11) is a ribosome biogenesis factor essential for optimal rDNA transcription and small subunit (SSU) pre-rRNA processing 1. During interphase, NOL11 localizes to the nucleolus and is required for cleavage steps generating mature 18S rRNA and maintaining nucleolar integrity 12. Mechanistically, NOL11 functions as a component of the human SSU processome and interacts with the ribosomal biogenesis factor hUTP4/Cirhin 1. Beyond ribosomal biogenesis, NOL11 has mitotic functions: it forms the NWC complex with WDR43 and Cirhin, which translocates to perichromosomal regions during mitosis to regulate centromeric Aurora B accumulation and ensure faithful chromosome 17 3. NOL11 also supports proper cell cycle progression by maintaining nucleolar integrity during interphase, which regulates Wee1 and Cdk1 phosphorylation to permit mitotic entry 2. Clinically, NOL11 deficiency causes ribosomopathy features including impaired craniofacial development through p53-dependent apoptosis of ribosome-impaired cells 4, and mutations in hUTP4/Cirhin that disrupt NOL11 interaction have been implicated in North American Indian childhood cirrhosis 1. In cancer contexts, NOL11 upregulation promotes gastric cancer and hepatocellular carcinoma progression via enhanced ribosome biogenesis 56.