The first-in-human clinical trial investigating MSLN-targeting CAR-macrophages (CAR-M) was proposed by Annunziata and colleagues, who studied peripheral blood mononuclear cell (PBMC)-derived CARs (MCY-M11), including macrophages, in patients with OC and mesothelioma (NCT03608618). The gene discussed is MSLN; the disease is mesothelioma.