Answer
It is both. Its folate-antagonist effects are used intensively against some cancers and differently to suppress inflammation in autoimmune disease.
Sources for this answer
- NHSNHS · NHS medicine guidance
- Methotrexate 100 mg/ml Injection — Current selected SmPCemc · Summary of Product Characteristics
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.