PROBLEM TO BE SOLVED: To provide a technique of evaluating TNF-α inhibitory effect caused by anti-TNF-α antibody preparations or soluble TNF-α/LTα receptor preparations by a reporter activity assaying method made by using the assessment system of a cultured cell, patient serum and TNF-α based on the finding in the molecular level of an immune response expression mechanism, and assessing the efficacy of the treatment.SOLUTION: The method for assessing the efficacy of a TNF-α-targeted drug includes a step of acting a mammalian cell for TNF-α activity assay and TNF-α on a target serum (wherein, the mammalian cell for TNF-α activity assay is such that the reporter gene thereof is under the control of a promoter that can be used for TNF-α activity assay, and is introduced so as to be expressed transiently or stably in the mammalian cell. The reporter gene is selected from the group consisting of luciferase, fluorescent protein and colored protein); and a
