Tight spatio-temporal co-expression of genes functioning in the same cell-biological process is a widespread phenomenon in eukaryotes [59], [60]. Synexpression groups have been found to be coordinated by trans-acting factors regulating common promoter elements [59], [60]. Strong correlation between content of RELA, NFKB1, IKKβ and IκBα mRNAs suggests common regulation of transcription for these four genes. This mechanism appears to operate in the PFC but not in the MC where no strong correlations between these four mRNAs were observed.
