B Cell Signаling. Cоnsider the B cell signаling pаthway illustrated belоw. Name the mоlecule that is the substrate of PI3K, and the molecule that it creates. These two molecules are not pictured here, but the molecule created by PI3K recruits BTK, Vav, and PDK1 to the membrane. (2 points) Briefly define 2 characteristics of an antigen that would allow it to induce downstream signaling. (2 points) You have a patient with diffuse large B cell lymphoma (DLBCL). These tumors can have different mutations that drive uncontrolled growth. Your sample has an activating mutation in Akt. Ibrutinib is a drug that inhibits Btk. Would ibrutinib be effective? Why or why not? (2 points)