F2RL1 and neoplasm: If ALK5 transactivation of PAR2 also operates in vivo in the tumor tissue to drive PAR2-dependent invasion and metastasis, then small molecule inhibitors of the ALK5 kinase, such as SB431542, LY2157299, or SD-208 would add another level of potency to a combined TGF-β/PAR2 inhibition approach.