The cytoskeletal extensions observed upon overexpression of CASC4 in Hela cells (Fig. 1g), and the correlation between PCSK7-CASC4 mRNA levels with breast cancer patients’ survival (Fig. 3a, b) suggested that CASC4 may impact cell migration and invasion, two essential steps of the metastatic process. This evidence concerns the gene PCSK7 and breast carcinoma.