[Isoform 1]: As a positive regulator of collagen fibrillogenesis, it is probably involved in the organization and remodeling of the extracellular matrix. ; [Isoform 2]: May positively regulate MAP-kinase activity in adipocytes, leading to enhanced adipocyte proliferation and reduced adipocyte differentiation. May also positively regulate NF-kappa-B activity in macrophages by promoting the phosphorylation and subsequent degradation of I-kappa-B-alpha (NFKBIA), leading to enhanced macrophage inflammatory responsiveness. Can act as a transcriptional repressor.