HTR2A and idiopathic pulmonary fibrosis: 2010; Dees et al. 2011). Lungs of patients with idiopathic pulmonary fibrosis (IPF) present increased expression of 5‐HT2A and 5‐HT2B receptors, with strong 5‐HT2B receptor localizations in densely fibrotic areas, so‐called fibroblastic foci (Fabre et al. 2008; Konigshoff et al. 2010). Furthermore, studies investigating 5‐HT2A and 5‐HT2B receptor antagonism in vivo have displayed promising antifibrotic effects (Fabre et al. 2008; Konigshoff et al. 2010).