Means by which a self-perpetuating disease might develop after infection were summarized by Singh and Girschick, including molecular mimicry; chronic poorly controlled inflammation; Th1 cytokines and other gene products, including IL-1, TNFα, collagenase, and prostaglandins elicited from macrophages; and osteoclast activation by IL-1 and TNFα [88]. The gene discussed is TNF; the disease is infection.