IDO1 and neoplasm: Alongside TILs, the expression of immune evasion molecules in the tumor microenvironment (TME), like programmed death-ligand 1 (PD-L1) and the indoleamine-2,3-dioxygenase enzyme 1 (IDO1), has been demonstrated to negatively influence TNBC prognosis (Beckers et al., 2016; Keenan and Tolaney, 2020; Alkhayyal et al., 2022).