FGF6 and systemic sclerosis: In addition, strong association signals have been reported between the fibroblast growth factor 6 gene (FGF6) and hemochromatosis, and functional validation showed that FGF6 regulates iron homeostasis and induces transcriptional regulation of ferredoxin, and its downregulation is associated with dysfunctional iron metabolism in systemic sclerosis and cancer cell [16].