WDR18 (WD repeat domain 18) is a core structural component of the rixosome complex, a multi-subunit protein assembly critical for ribosome biogenesis. WDR18 functions as part of the PELP1-TEX10-WDR18 complex within the larger human rixosome, which includes LAS1L and NOL9 1. The complex is recruited to pre-60S ribosomal subunits where it coordinates nucleolar maturation of 28S rRNA and subsequent nucleoplasmic transit of the pre-60S ribosomal subunit 2. Structurally, WDR18 serves as a critical scaffold interface, with two contact regions binding TEX10 and a C-terminal helix interacting with the catalytic LAS1L subunit 1. The rixosome's activity is regulated by SUMO-dependent modification of PELP1, where SENP3-mediated desumoylation controls dynamic association with the remodeling AAA-ATPase MDN1 3. Beyond ribosome biogenesis, WDR18 is implicated in disease pathogenesis. Genetic studies show WDR18 expression in CD4+ T cells inversely correlates with risk for Crohn's disease and asthma, suggesting potential therapeutic value as a drug target 4. Additionally, de novo WDR18 variants have been identified in individuals with Cornelia de Lange syndrome-like phenotypes 5, and upregulated WDR18 promotes hepatocellular carcinoma development through Wnt/β-catenin pathway activation 6.