A transient knockdown of ESRP1 in human breast cancer MCF7 and human pancreatic adenocarcinoma BxPC-3 cells resulted in a shift of expression from CD44v (containing exon v6) to CD44 isoform 4 without affecting total CD44 level (Preca et al., 2015). This evidence concerns the gene ESRP1 and breast carcinoma.