To determine the extent of QKI autoregulation in the context of breast and prostate cancer EMT, we examined the effect of knockdown of QKI-5 in a mesenchymal prostate cancer cell line (PC-3), a mesenchymal breast cancer cell line (MDA-MB-231), and a mesenchymal breast cell line (mesHMLE). This evidence concerns the gene QKI and breast carcinoma.