DDIT4 and idiopathic pulmonary fibrosis: CTD-2528L19.6 may regulate fibroblast activation in IPF progression by mediating the expression of some mRNAs, such as LRRC8C, DDIT4, THBS1, S100A8 and TLR7. Our results suggest that during early-stage, CTD-2528L19.6 was up-regulated to prevent IPF, while CTD-2528L19.6 was down-regulated to promote fibroblast activation from early-stage to advanced-stage transition.