An emerging family of regulatory proteins referred to under the CCN acronym (for Connective tissue growth factor (CTGF), Cystein rich protein (Cyr61), and Nephroblastoma overexpressed gene (nov))¹ has been uncovered over the past few years.

The CCN family comprises both positive and negative regulators sharing a common multimodular organisation. New members of the CCN family have been described recently. More are to come.

The chicken CEF10 and homologue murine cyr61 genes were first identified as immediate early genes induced by the pp60^v-src oncogene and serum growth factors, respectively.^{2, 3} The CYR61 protein was shown to promote cell adhesion, migration, and proliferation, probably through potentiating platelet derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) activities.⁴

Human ctgf was also identified as an immediate early gene encoding a connective tissue growth factor (CTGF)⁵ showing mitogenic activity for human umbilac vein endothelial cells (HUVECs) and fibroblasts in culture.⁶

The nov gene …