CUGBP1 is an RNA-binding protein controlling alternative splicing, mRNA translation and stability. In this work we used a motif scoring approach to identify putative CUGBP1 binding sites for genes located on the human chromosome 12. This allowed us to identify the gene CD9 as a presumptive target for CUGBP1-mediated regulation. In a number of cancers. the tetraspanin CD9 is down-regulated, an event correlated with a bad prognostic. Using a combination of biochemical approaches and CUGBP1 knockdown, we showed that CUGBP1 directly controls CD9 expression. (C) 2010 Elsevier Inc. All rights reserved.