Promotes maintenance and self-renewal of pluripotent embryonic stem cells (ESCs), downstream of LIF/STAT3 (PubMed:21425410). Maintains the pluripotency state of ESCs by repressing DNA methylation through the regulation of UHRF1 stability. Mediates the proteasomal degradation of UHRF1. Is required for the establishment of the blastocyst (PubMed:28604677). Interacts with UHRF1. Seems to be specific to pluripotent tissues in the early embryo. Not detected in somatic tissues. Expressed in early embryos at the 4-cell, blastocyst (3.5 dpc) and epiblast (7 dpc) stages (PubMed:12620990, PubMed:21425410). Expression is restricted to the interior part of the morula and the inner cell mass (ICM) of the blastocyst (PubMed:21425410). Detected in primordial germ cells (at 10 dpc) and undifferentiated embryonic stem cells (PubMed:12620990, PubMed:21425410). Embryonic lethality due to a developmental arrest during the establishment of the blastocyst. Belongs to the PRAME family. Sequence of unknown origin in the N-terminal part.