In the early phase of BLM-induced pulmonary fibrosis, Tanaka et al. indicated that the deficiency of CHOP (CCAAT/enhancer binding protein homologous protein), an endoplasmic reticulum (ER)-stress-induced transcription factor, suppressed BLM-induced pulmonary fibrosis via inhibition of early events such as the induction of apoptosis and inflammatory-related genes and accumulation of BALF cells [16]. Here, DDIT3 is linked to pulmonary fibrosis.