We also found that serum and PDGF-BB, both implicated in fibroblast activation in vitro (48, 49), potently stimulated FOXM1 and BIRC5 expression in IPF fibroblasts, and this effect was abrogated by NFATc1 silencing (Figure 6B). Here, NFATC1 is linked to idiopathic pulmonary fibrosis.