Highly expressed in stem cells where it may be involved in regulation of pluripotency. In embryonic stem cells (ESCs), important for normal expression of the pluripotency regulators POU5F1/OCT4 and KLF4. Also important for expression of the ectodermal marker gene NES and the endodermal marker gene GATA4. Promotes stem cell proliferation in vitro. Interacts with NPM1 and NCL. As stem cells differentiate, translocates from the nucleolus to the nucleus and then to the cytoplasm. Colocalizes with NPM1 and NCL in the nucleolus. It is uncertain whether Met-1 or Met-14 is the initiator. Truncated N-terminus.