TNF and rheumatoid arthritis: Rheumatoid arthritis patients receiving TNF-α blockers were reported to become infected with Pneumocystis carinii[32], Legionella pneumophila[33], [34], M. tuberculosis[35], Echinococcus multilocularis[36], Histoplasma capsulatum[37], non-typhi Salmonella [38], [39], and non-tuberculous mycobacteria [40]–[43].