ABSTRACT: Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Pluripotent stem cells can be induced from somatic cells, providing an unlimited cell resource for regenerative medicine. However, genetic manipulation and difficult-to-manufacture strategies used in reprogramming limit their clinical applications. Here, we show pluripotency can be induced from mouse somatic cells by specific small-molecule compounds. The completely chemically-induced pluripotent stem cells (CiPSCs) can be stably maintained in embryonic stem cell (ESC) culture medium and resemble ESCs in terms of their gene expression profiles, epigenetic status, and potential for differentiation and germline transmission. These findings suggest that exogenous master genes are dispensable for cell fate reprogramming and pave the way for the clinical application of somatic reprogramming techniques. Chemicals' acronyms: V, VPA; C, CHIR; 6, 616452; T, tranylcypromine; F, FSK; Z, DZNep; P, PGE2; R, RG108; S, SRT1720; M, 2-Me-5HT; D, D4476; B, Sodium butyrate. To compare the global gene expression pofile of mouse embryonic fibroblasts (MEFs), mouse adult lung fibroblasts (MAFs), mouse neonatal fibroblasts (MNFs), adipose-derived stem cells (ADSCs), chemical induced pluripotent stem cells (CiPS), embryonic stem cells (ESCs) and OSKM-iPSCs. We profiled the mRNA expression of each sample by microarray (Mouse OneArray® v2, Phalanx). Different sample set was normalized for different purpose. Set1: MEFs1, CiPS34, MNF CIPS7, CiPS50 CiPS21, OSKM-iPS1 and ESCs1 were analyzed, each sample have three replicates; Set2: MNFs, MAFs, ADSCs, MNF CiPS1, MAF CiPS3, CiPS45, ADSC CiPS2, OSKM iPS2 and ESCs2 were analyzed, each sample have three replicates; Set3: WT MEFs, ESCs3, CiPS WT1 and CiPS WT2 were analyzed, each sample have two replicates; Set4: MEFs2, SKM-FSK1, SKM-FSK2 and ESCs4 were analyzed, each sample have three replicates; Set5: MEFs3, ESCs5, CiPSCs, D12, D20 and D32 were analyzed, each sample have two replicates.