RBM19 (RNA binding motif protein 19) is an RNA-binding protein with multiple RNA-binding domains that functions primarily in ribosomal biogenesis and cell proliferation regulation. Structurally, RBM19 contains six RNA-binding domains in animals with conserved linker regions that position these domains at functionally important distances 1. The protein localizes to the nucleolus during interphase and the perichromosomal sheath during mitosis, consistent with its role in ribosome biogenesis 2. RBM19 is aberrantly expressed in multiple cancers and plays pathogenic roles in tumor progression. In hepatocellular carcinoma (HCC), RBM19 was identified as one of 11 differentially expressed RNA-binding proteins associated with poor overall survival and incorporated into a prognostic risk score model 3. In prostate cancer, RBM19 promotes progression under docetaxel treatment by binding to lncRNA SNHG21, enhancing its stability and preventing PIM1 protein degradation, thereby promoting mitochondrial homeostasis and drug resistance 4. RBM19 expression patterns indicate its role in proliferation: it is expressed throughout the embryonic gut epithelium but becomes restricted to intestinal crypts containing progenitor cells in adults, with widespread expression in colorectal carcinomas 2. Clinically, RBM19 variants have been associated with lung function and chr12 obstructive pulmonary disease susceptibility 5. These findings suggest RBM19 represents a potential therapeutic target across multiple malignancies.