Review on biologicals: PMID 15127338, 16887405, 19634383, 21531225, 21597375, 22718926, 24101863. Guide when starting treatmenta at PMID 24667275. Robust evidence for causality exists regarding opportunistic infections, including bacterial infection and tuberculosis, and for the devlopment of autoimmunity. As for ILD and serosal involvement, although a temporal association with exposure may exist in some cases, evidence for causality is tenuous or disputed. For those cases exposed to methotrexate concomitantly, drug causality assessment can be difficult. Ruling out an infection is important in all cases. Risk assessment for TB well-delineated but suboptimally implemented (PMID 19634383). Tuberculosis reinfection can occur despite a history of optimal prophylaxis at onset of treatment. Anti-TNF agent-induced infection available at PMID 15127338, 15523118, 18241628, 20381217, 24655394 and 25630559