RBM35A, also known as ESRP1, is a mRNA splicing factor that with its related protein RBM35B (ESRP2) are coordinators of an epithelial cell-type-specific splicing program. RBM35A contains three putative RNA recognition motifs and acts by directly binding specific sequences in mRNAs. RBM35A is involved in posttranscriptional regulation of a number of genes such as FGFR2, CD44, CTNND1, and ENAH by exerting a differential effect on protein translation via 5' UTRs of mRNAs. Other recent studies have shown that RMB35A may also act as a novel tumor suppressor.