Human T lymphocytes predominantly express the CREMα isoform, and these levels are increased in T cells from SLE patients [22–24]. Until recently, CREMα was considered to act as a transcriptional repressor, but recent evidence indicates that CREMα can activate the transcription of certain cytokine genes in CD4+ T cells. Although it has been proposed that the presence of the τ domains within CREM isoforms determines their capacity as transcriptional activators [25], experiments measuring the differential effects of CREM variants with and without τ domains on the same gene promoter have yet to be performed.
