c-Rel: Productsc-Rel/Rel is a 69-kDa class II member of the Rel/NF-kB family of transcription factors. All Rel family members contain a RHD (Rel Homology Domain) that is involved in dimerization, DNA and IkB binding, and nuclear localization. Class II members contain an additional C-terminal transcriptional activation segment. Rel homodimerizes and heterodimerizes with multiple family members. Following dimerization, Rel complexes initiate transcription by acting on decameric DNA motifs termed kB-binding sites.