PTK2 and breast carcinoma: In addition, FAK cooperated with the Krüppel-like factor 8 (KLF8) in order to enhance the cell surface presentation of active matrix metallopeptidase 14 (MMP14) and the activity of its target substrate matrix metallopeptidase 2 (MMP2), toward the stimulation of breast cancer cell invasion both in vitro and in vivo [114].