Finally, in a purely subjective hypothesis-generating fashion, we looked for nonhematopoietic cell lineage–dependent (endothelial cell and myofibroblast) qualitative differences in STING expression in histologic samples from healthy controls donors and patients with PAH and idiopathic pulmonary fibrosis (IPF) with or without PH (Supplemental Figure 2, A and B; control donor and patient demographics in Supplemental Table 1). Here, STING1 is linked to pulmonary arterial hypertension.