This gene encodes a spliced long non-coding RNA transcribed from a bidirectional promoter shared with Foxf1 on the opposite strand. The encoded transcript is essential for normal development of the heart and body wall. It is thought to act by binding to polycomb repressive complex 2 (PRC2) and/or TrxG/MLL complexes to promote the methylation of the promoters of target genes, thus reducing their expression. It plays a role in cell fate determination in tissues derived from the lateral plate mesoderm. Knockout models reveal loss of this gene is lethal in mice. Alternatively spliced transcript variants have been identified. [provided by RefSeq, Dec 2014]