On the other hand, S1P is capable of activating the matriptase, a serine protease with an important role in tissue remodeling [143], whose overexpression found in breast cancer tissue is associated with a poor prognosis [144] through activation of PAR-2-NF-κB and PI3K-Akt-mTOR, pro-inflammatory and pro-oncogenic signaling, respectively [145]. Here, ST14 is linked to breast cancer.