RBM15 (RNA binding motif protein 15) is a key regulator of N6-methyladenosine (m6A) RNA methylation that plays critical roles in gene expression control and cellular differentiation. As a component of the methyltransferase complex, RBM15 binds target RNAs and recruits the m6A methylation machinery to specific sites, particularly at consensus motifs 1. RBM15 is essential for X chromosome 1, where it binds Xist RNA and facilitates m6A methylation that recruits YTHDC1 reader protein to promote transcriptional silencing 1. The protein regulates hematopoietic stem cell homeostasis and megakaryocyte differentiation through m6A-mediated control of alternative splicing 2. RBM15 also influences chr1 regulation by working with RBFOX2 and PRC2 complex for gene silencing 3. Clinically, RBM15 is implicated in multiple cancers where its overexpression promotes tumor progression. In acute myeloid leukemia, RBM15 supports leukemia stem cell self-renewal 3. In lung adenocarcinoma, elevated RBM15 facilitates osimertinib resistance through m6A modification of SPOCK1 mRNA 4. Additionally, RBM15 contributes to glioblastoma radioresistance by mediating proneural-to-mesenchymal transition in glioma stem cells 5. These findings establish RBM15 as both a fundamental regulator of RNA metabolism and a potential therapeutic target in cancer treatment.