WDR43 (WD repeat domain 43) is a multifunctional protein with dual roles in ribosome biogenesis and transcriptional regulation. Primarily, WDR43 functions as a ribosome biogenesis factor essential for small subunit (SSU) processome assembly and nucleolar processing of pre-18S ribosomal RNA 1. It is required for optimal pre-rRNA transcription by RNA polymerase I 12 and coordinates hyperactive transcription with ribogenesis 1. Beyond its classical role, WDR43 acts as a chr2-associated RNA-binding protein recruited by nascent transcripts to active promoters, where it facilitates P-TEFb release and RNA polymerase II elongation to maintain high-level gene expression 3. WDR43 is essential for stem cell pluripotency and embryonic development 4. In disease contexts, WDR43 is significantly elevated in multiple cancers. In colorectal cancer (CRC), overexpression promotes chemoresistance and tumor growth by enhancing p53 ubiquitination through MDM2 interaction 5, while also promoting cell survival via vimentin regulation 6. In non-small cell lung cancer, elevated WDR43 drives malignant progression by interacting with CDK2 7. In acute myeloid leukemia, WDR43 is synthesized through codon-biased translation driven by ALKBH1, promoting leukemogenesis and drug resistance 8. WDR43 is also identified as a hub gene in pulmonary arterial hypertension pathogenesis 9.