The IL1R1-targeted drugs anakinra and lenvatinib are undergoing phase I/II/III trials for rheumatoid arthritis, pulmonary arterial hypertension, hydradenitis supplementation, and unstable stage III or stage IV melanoma (Table S10, Supplemental Digital Content, https://links.lww.com/MD/Q306). Here, IL1R1 is linked to pulmonary arterial hypertension.