IDO1 and neoplasm: Since striking evidence indicates that (MSC‐derived) IDO contributes to tumor immune escape,15, 16, 17 our study focussed on ATP‐enhanced IDO expression in MSCs and its impact on lymphocyte proliferation which was assessed by culturing PBL in conditioned media derived from MSCs stimulated with predominant factors within inflammatory necrotic tissue of tumor, that is, IFNγ as a prototype of inflammation‐associated cytokines plus ATP36, 37 as a crucial DAMPs family member which is found at thousand times higher concentrations in tumor tissue.31, 32, 33