ANO1 and idiopathic pulmonary arterial hypertension: First, we verified the presence of TMEM16A in von Willebrand Factor positive (vWF+) cells from healthy donors and IPAH patients employing immunofluorescence staining in 3D precision-cut lung slices (PCLS), as well as lung sections and PAECs (Figure 2a–c, Figure S2a–e and Table S4).