MST1 and neoplasm: Moreover, it has recently been reported that MST1/2 (mammalian Ste20-like kinase 1/2), a component of the tumor-suppressing Hippo signaling pathway, is a novel substrate of PAR1b.111 Therefore, further investigation may reveal the involvement of perturbed MST1/2-LATS1/2-YAP/TAZ signaling induced by the CagA-PAR1b complex in the pathobiological action of the CagA protein.