F2R and lung carcinoma: In addition, studies with breast, gallbladder and ovarian cancer cell lines have shown that MMPs (MMP-1, MMP-9, MMP-13, MMP-14) may activate PARs signaling, especially by cleavage of PAR-1 (majority of tumors) or PAR-2 (lung cancer) [15, 39, 52, 71].