The existence of P. acnes was found in formalin-fixed paraffin-embedded (FFPE) sections of patients from various countries but was rarely detected in tuberculosis and lung cancer patients.387,388 Since Treg cells infiltrate heavily in patients with sarcoidosis, accompanied by a high level of associated cytokines, such as IL-10 and TGF-β, P. acnes may induce Treg cells by releasing propionic acid, resulting in the formation of granulomas in sarcoidosis.389. Here, IL10 is linked to sarcoidosis.