IL13 and idiopathic pulmonary fibrosis: Neighbors et al., in a post-hoc assessment of the CAPACITY (n = 184) and ASCEND (n = 229) trials, also investigated the association between the levels of various biomarkers (CCL13, CCL17, CCL18, CXCL13, CXCL14, COMP, interleukin 13, MMP3, MMP7, osteopontin, periostin, and YKL40) and absolute decline in FVC (%) over 12 months in patients with IPF treated with pirfenidone; however, they were unable to find biomarkers associated with the treatment response to antifibrotic agents [13].