NR1H4 and idiopathic pulmonary fibrosis: Interestingly, in line with our findings regarding LXR/RXR and FXR/RXR and the differentiation and activation of macrophages in IPF [20], Venosa et al. reported that treatment with fibrotic substances induces a time-related increase in large vacuolated macrophages and the accumulation of oxidized phospholipids in lung macrophages and epithelial cells, promoting the formation of foamy macrophages and their M2 activation.