CCN2 and infection: The clearance of Ct infection is generally accepted to be mediated by interferon gamma (IFNγ) [9–11] with epithelial and lymphoid cells generating a strong pro-inflammatory Type 1 response that includes production of growth factors, such as platelet-derived growth factor (PDGF), connective-tissue growth factor (CTGF) and tumour necrosis factor alpha (TNFα) [12–15].