Background: Induced pluripotent stem cells (iPSCs) are generated from somatic cells and regain the pluripotent potential through reprogramming treatments by different cocktails, e.g.the ectopic expression of embryonic stem cell enriched transcriptional factors (TFs).It has been discovered that additional replenishment of the four TFs, i.e.Oct4, Sox2, Klf4 and c-Myc is sufficient for the conversion of somatic cells, whilst lineage specifiers which are rivals of pluripotency and suppress the stability of stem cell state can substitute for pluripotency factors Oct4 and Sox2 in the reprogramming experiments.The lineage markers establish a balance between two counteracting lineages and induce pluripotency.Although extensive combinations of reprogramming factors have been identified to facilitate reprogramming, the underlying mechanisms for the generation of iPSCs are still unclear.