Acts as a transcriptional repressor (PubMed:17974029). Has mitogenic activity for fibroblasts (PubMed:11751870, PubMed:26845719). Heparin-binding protein (PubMed:15491618). Does not have mitogenic activity for fibroblasts (PubMed:26845719). Does not bind heparin (PubMed:26845719). Has mitogenic activity for fibroblasts (PubMed:26845719). Heparin-binding protein (PubMed:26845719). Monomer, and domain-swapped homodimer (PubMed:17270212). Interacts with nuclear proteins NCL and YBX1/YB1 (PubMed:26845719). Interacts with cytoskeletal proteins such as actin, dynein, tubulin and vimentin (PubMed:26845719). Interacts with cytoskeletal proteins such as dynein and tubulin but does not interact with actin or vimentin (PubMed:26845719). Secreted by exosomes and is located inside the exosome (PubMed:27926477). May also be secreted as free protein via an as yet unknown pathway (PubMed:27926477). Secreted by exosomes and is located on the outer exosome surface. Secreted by exosomes and is located on the outer exosome surface. Ubiquitous. The PWWP domain harbors the heparin-binding sites and is responsible for DNA-binding, while the C-terminal region is essentially unstructured. The N-terminal region does not contain a typical signal sequence but is required for secretion (By similarity). It also determines exosomal location (PubMed:26845719). Sumoylated with SUMO1. Sumoylation prevents binding to chromatin. Phosphorylation at Ser-165 is likely to be required for secretion. Belongs to the HDGF family.