CD8A and neoplasm: Because miR-448 downregulated IDO1 protein expression and suppressed IDO1 function by targeting IDO1 (Figs. 5e, 6a and b, and Additional file 1: Figure S7), and the IHC results strongly suggested that IDO1 modulated tumor CD8+ T cell immunity, it is rational to hypothesize that miR-448 can affect the CD8+ T cell response by suppressing IDO1 expression.