MAPK3 and cancer: Previous studies have shown that NF-κB, ERK1/2 and PI3K-AKT are activated downstream of Cyr61 and are associated with proliferation in cancer cells15, 37, 38, 39; thus, we probed downstream signaling pathway(s) using known inhibitors of several pathways, including Ly294002 (an inhibitor of the PI3K/AKT pathway), PDTC (an inhibitor of NF-κB activation), and PD98059 (an inhibitor of ERK1/2).