Provided are a method for screening agents for the prevention or treatment of diseases caused by interleukin 6, interleukin 13, TNF, G-CSF, CXCL1, CXCL2, or CXCL5 and an agent for the prevention or treatment of diseases caused by interleukin 6, interleukin 13, TNF, G-CSF, CXCL1, CXCL2, or CXCL5. A method for screening agents for the prevention or treatment of diseases caused by interleukin 6, interleukin 13, TNF, G-CSF, CXCL1, CXCL2, or CXCL5 having as the index at least one selected from the group consisting of changes in the expression of the MEX3B gene or MEX3B protein and changes in the function of the MEX3B protein.