This section provides detailed supplemental experimental procedures, figures, and references for a study on the role of Nanog in the pluripotent ground state. The procedures cover cell culture conditions, cell fusion, retroviral infection, embryo collection, immunoblotting, immunofluorescent staining, and RT-PCR/qRT-PCR. Key findings include the demonstration that Nanog is essential for maintaining pluripotency, its role in somatic cell reprogramming, and its expression in various stages of differentiation. The supplemental figures and legends provide visual support for these findings, including data on Nanog expression, gene regulation, and the efficiency of reprogramming. The references cited include key studies on stem cell biology and reprogramming.This section provides detailed supplemental experimental procedures, figures, and references for a study on the role of Nanog in the pluripotent ground state. The procedures cover cell culture conditions, cell fusion, retroviral infection, embryo collection, immunoblotting, immunofluorescent staining, and RT-PCR/qRT-PCR. Key findings include the demonstration that Nanog is essential for maintaining pluripotency, its role in somatic cell reprogramming, and its expression in various stages of differentiation. The supplemental figures and legends provide visual support for these findings, including data on Nanog expression, gene regulation, and the efficiency of reprogramming. The references cited include key studies on stem cell biology and reprogramming.