In a subsequent study, CpG-ODN treatment was observed to significantly reduce AGO1 expression in rapid progressor lung fibroblasts, further supporting a role of TLR9 activation in the aberrant profibrotic phenotype of IPF fibroblasts from rapid progressor IPF patients (Hogaboam et al., 2012). Here, AGO1 is linked to idiopathic pulmonary fibrosis.