BUD13 is a spliceosome-associated protein that plays crucial roles in pre-mRNA splicing and gene regulation. As an RNA-binding protein, BUD13 functions as a component of both major and minor spliceosomes, facilitating the splicing of U2-type and U12-type introns 1. BUD13 specifically acts to counter intron retention (IR) by promoting successful splicing, particularly at introns with specific characteristics, thereby regulating mature transcript levels of target genes 1. Recent studies have identified BUD13 as forming nuclear condensates, suggesting additional roles in nuclear organization and compartmentalization 2. Beyond splicing, BUD13 functions as an endogenous inhibitor of the tumor suppressor Fbw7, stabilizing oncogenic substrates and interfering with Fbw7-Cul1 complex formation 3. Disease relevance includes associations with metabolic syndrome through genetic polymorphisms affecting lipid metabolism 456. Cancer studies reveal that elevated BUD13 expression correlates with poor prognosis in multiple cancer types, including hepatocellular carcinoma, and somatic gain-of-function mutations (R156C, R230Q) promote oncogenesis by disrupting Fbw7 function 73. BUD13 also modulates immune responses by regulating Irf7 splicing and type I interferon signaling 1.