The NFκB pathway regulates inflammation, dendritic cell (DC) development and function, and thymic selection and regulatory T cell production. The pathway is described in the text. Deficient strains marked in red display defects in thymic organization and negative selection with increased numbers of peripheral autoreactive T cells. The two main NFκB activation pathways are marked in blue. IL, interleukin; IRAK, IL-1 receptor-associated kinase; MAPK, mitogen-activated protein kinase; mTEC, medullary thymic epithelial cell; NFκB, nuclear factor κB; NIK, NFκB inhibitory kinase; TLR, toll-like receptor; TNF, tumor necrosis factor; TRAF6, TNF receptor associated factor 6.