Compared with shVector cells, IDO1+ cells showed more progressive tumor growth, strong IDO1 expression, a low relative Trp concentration, a high relative [Kyn]/[Trp] ratio, and a low CD8+T proportion in TIL (panel D); however, in shIDO1 cells, these phenomena in IDO1+ cells were reversed (panel D). Here, CD8A is linked to neoplasm.