IFRD2 (Interferon-related developmental regulator 2), also known as SKMC15, is a 442 amino acid soluble nuclear protein. IFRD2 is ubiquitously expressed and contains a β-catenin-like repeat, which may indicate an involvement in APC signaling. With 75% homology to IFRD1, IFRD2 may also regulate expression of surface adhesion molecules involved in differentiation and fusion of myogenic satellite cells. Although the gene encoding IFRD2 undergoes overlapping homozygous deletions in many lung cancer cell lines, IFRD2 exhibits no loss-of-function mutations in cancer cells, suggesting a possible role in tumor progression.