Connective tissue growth factor (CTGF) is another important profibrotic growth factor in this context and it has been shown that 7 days post-MI, levels of CTGF in the lungs increase significantly with remodelling of the pulmonary arteries, and localise predominantly to alveolar macrophages and interstitial fibroblasts, with alveolar macrophages in particular governing the spread of fibrosis from the heart to the lung vasculature and increasing the risk of pulmonary hypertension [1]. This evidence concerns the gene CCN2 and pulmonary arterial hypertension.