<;P>;PROBLEM TO BE SOLVED: To elucidate the target molecule of IP<;SB>;3<;/SB>;receptor binding protein (IRBIT), to elucidate the important biological function of IRBIT and to establish the control of the function. <;P>;SOLUTION: This composition includes IRBIT, a nucleic acid that control the expression/translation of IRBIT or a composition including the antibody against IRBIT and is used for controlling at least one of intracellar biological function selected from the group consisting of (1) protein synthesis, (2) inositol phospholipid metabolism and (3) intracellar pH. <;P>;COPYRIGHT: (C)2008,JPO&INPIT