CASP3 and idiopathic pulmonary fibrosis: Caspase 3/7 and TUNEL assay revealed that enhanced cell death caused by A. alternata extract was likely due to necrosis, and 7‐AAD assay and the use of sodium pyruvate for ATP generation further supported our findings that IPF fibroblasts become resistant to A. alternata extract‐induced necrotic cell death.