The use of TNF antagonists has been associated with an increased incidence of opportunistic infections, including Staphylococcus aureus infections, listeriosis, Legionella pneumophila infections, nocardiosis and non-tuberculous mycobacterial infections, cryptococcosis, histoplasmosis, coccidioidomycosis, pneumocystosis, histoplasmosis, candidiasis, and aspergillosis, but also with reactivation of chronic HBV and latent tuberculosis infections (9). Here, TNF is linked to pneumocystosis.