Mechanistically, it was found that p140Cap behaves as a novel binding partner in the cell machinery recruiting Csk and Src, through the binding of Csk on p140Cap with the tyrosines inserted in EGLYA/EPLYA motif and of Src with the proline rich domains, respectively, regulating in this way their activity and downstream signaling in breast cancer cells (Figure 3A; Di Stefano et al., 2007; Repetto et al., 2013). Here, CSK is linked to breast carcinoma.