ATF6 and idiopathic pulmonary fibrosis: Another observation was that, while LBH589-treatment was associated with the induction of ER stress- and apoptosis-related genes in IPF-fibroblasts, as shown by increases in ATF6- (activating transcription factor-6, Fig 3I), CHOP- (C/EBP homologous protein, Fig 3J), DR5- (death receptor 5, Fig 3K), PUMA- (p53 upregulated modulator of apoptosis, Fig 3L) and CIP1/p21 transcripts (Fig 3M), treatment with pirfenidone did not elicit this kind of response.