HuR immunoprecipitation (Fig. 3b and Supplementary Fig. 5h) followed by RT-PCR and qRT-PCR confirmed that HuR binds to different portions of KGA and GAC 3′-UTR sequences in prostate and breast cancer cellular models (Figs. 3c, e and  3d, f, respectively). This evidence concerns the gene ELAVL1 and breast cancer.