Are haplotypes in a single methotrexate pathway more predictive for response in rheumatoid arthritis than in different pathways

Letter to the editor with respect to: Lima A, Bernardes M, Azevedo R, Seabra V and Medeiros R. Moving toward personalized medicine in rheumatoid arthritis: SNPs in methotrexate intracellular pathways are associated with methotrexate therapeutic outcome. Pharmacogenomics 17(15), 1649-1674 (2016).