IDO1 and neoplasm: These points were addressed to some extent in a report on cultures of tumor cell lines (3LL, A549, and NCI-H292), where simvastatin was able to reduce the number of tumor cells and increase the production of IL-10 and TGF-β in a dose-dependent manner, associated with increased expression of IDO and foxp3 and therefore accompanied by increased expansion of Tregs [53].