Figure 1. Canonical and non-canonical NFκB signalling pathways. The canonical pathway can be activated by cytokines, or molecules of bacterial or viral origin such as TNFα. IKKγ/NEMO and IKKβ are essential for the phosphorylation and subsequent ubiquitination and proteosomal degradation of IκB, leading to nuclear translocation of the RELA-p50 transcription factor complex. The non-canonical pathway is activated by a more specific set of stimuli such as lymphotoxin β (LT-β). NIK and IKKα are essential for phosphorylation and subsequent ubiquitination and proteosomal processing of p100 giving rise to a transcriptionally active RELB-p52 complex.