Abstract: [Problem to be Solved by the Invention] To predict the efficacy of a rheumatoid arthritis therapeutic agent, or find a simple and highly reproducible hiomarker that can be used to assess the activity of disease conditions and states of rheumatoid arthritis, and provide an effective method. [Solution] A method for predicting the efficacy of a rheumatoid arthritis therapeutic agent on a.

Abstract: The object of the invention is to find a simple biomarker with high reproducibility with regard to a method for evaluating the activity of the condition and progression of rheumatoid arthritis disease and provide an effective evaluation method therefor. The invention is to provide a method for determining the value of a rheumatoid arthritis-linked indicator in a subject, the method being characterized by comprising a step for measuring the amount of expression of the FAM20A gene in blood collected from the subject, a step for analyzing the measured amount of expression using a gene expression profile that is prepared in advance and correlates with the indicator and a step for estimating the value of the indicator in the subject on the basis of the analysis results.