FLI1 and pulmonary arterial hypertension: Abnormal expression of FLI-1 in ECs may play a role in several diseases (Table 3); for example, low FLI-1 expression leads to SSc by promoting fibrosis and vascular lesions, to PAH by promoting the local inflammatory state and vascular lesions, and to tumour metastasis by promoting the EndMT process; and high FLI-1 expression leads to LN by promoting a local inflammatory state (Fig. 4).