Takahashi, Miho, et al. “Early Erythrocyte Methotrexate Polyglutamate-4 Predicts Treatment Response and Is Influenced by GGH 401C>T Genotype in Patients With Rheumatoid Arthritis”. Archives of Rheumatology, vol. 41, no. 2, Mar. 2026, pp. 125-33, doi:10.5152/ArchRheumatol.2026.25173.