Mouse ribosomal protein (Rp) L6 promoter contains several transcription binding sites, in addition to common features shared by other Rp promoters, suggesting that RpL6 promoter might be induced by some extracellular elements. To access this question, Jurkat and K562 cells were cultured with α-IFN, γ-IFN or EPO and looked at RpL6 expression by Northern hybridization as well as reporter assay. Treatment with these cytokines upregulated RpL6 mRNA was detected by Northern hybridization. Reporter vectors with promoter fragments containing different transcription factor binding sites were constructed and transiently transfected to Jurkat and K562 cells cultured with α-IFN, γ-IFN or EPO. Luciferase activity was examined in the cell lysates. The promoter activity of RpL6 was elevated significantly after cytokine treatment. These results suggest that cytokines may increase the transcription level of RpL6 gene via induction of the RpL6 promoter.