Although a temporal association with exposure to the drug may exist, evidence for causality is not strong. For those cases exposed to methotrexate concomitantly, drug causality assessment is even more difficult. Ruling out an infection is crucially important. ILD cases with combo DMARD treatments (methotrexate + TNF-alpha antagonist) (e.g. PMID 24626274) are not included due un uncertain causality. Evidence accumulates from epidmiologic studies indicating that anti-TNF agents are not associated with the development of ILD (PMID 23359391)