A surgical stapling instrument , comprising: a housing ; a closure system operably supported by said housing and configured to generate closing and opening motions; an elongate shaft assembly operably interfacing with said housing, said elongate shaft assembly comprising a spine and a closure tube assembly , wherein the spine is configured to slidably support a firing member therein, wherein the closure tube assembly extends around the spine, and wherein the spine slidably supports the closure tube assembly, the closure tube assembly comprising an end effector closure sleeve , wherein the closure tube assembly, including the end effector closure sleeve, is axially movable in response to applications of said closing and opening motions thereto; a surgical end effector comprising: an elongate channel operably interfacing with said elongate shaft assembly and configured to operably support a surgical staple cartridge therein; and an anvil movably supported on said elongate channel for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument is further characterized in that it comprises at least two opening cams protruding from said end effector closure sleeve such that upon application of said opening motion to said end effector closure sleeve, said at least two opening cams operably interface with corresponding cam surfaces on said anvil in a first direction to move said anvil to said open position and upon application of said closing motion to said end effector closure sleeve, said end effector closure sleeve operably interfaces with said anvil in a second direction to cause said anvil to move to one of said closed positions. a housing ; a closure system operably supported by said housing and configured to generate closing and opening motions; an elongate shaft assembly operably interfacing with said housing, said elongate shaft assembly comprising a spine and a closure tube assembly , wherein the spine is configured to slidably support a firing member therein, wherein the closure tube assembly extends around the spine, and wherein the spine slidably supports the closure tube assembly, the closure tube assembly comprising an end effector closure sleeve , wherein the closure tube assembly, including the end effector closure sleeve, is axially movable in response to applications of said closing and opening motions thereto; a surgical end effector comprising: an elongate channel operably interfacing with said elongate shaft assembly and configured to operably support a surgical staple cartridge therein; and an anvil movably supported on said elongate channel for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument is further characterized in that it comprises an elongate channel operably interfacing with said elongate shaft assembly and configured to operably support a surgical staple cartridge therein; and an anvil movably supported on said elongate channel for selective movement relative thereto between an open position and closed positions and wherein said surgical instrument is further characterized in that it comprises at least two opening cams protruding from said end effector closure sleeve such that upon application of said opening motion to said end effector closure sleeve, said at least two opening cams operably interface with corresponding cam surfaces on said anvil in a first direction to move said anvil to said open position and upon application of said closing motion to said end effector closure sleeve, said end effector closure sleeve operably interfaces with said anvil in a second direction to cause said anvil to move to one of said closed positions. <EOS>