IDO1 and neoplasm: However, most noticeable were the number of studies indicating a higher impact of the immune response in tumors of NSND compared to SD, with the description of the interferon γ (INFγ) and nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NFKB) pathways, including interleukin‐10 (IL‐10), programmed death‐1 (PD‐1), programmed death‐ligand 1 (PD‐L1), indoleamine 2,3‐dioxygenase 1 (IDO‐1), and tumor‐infiltrating lymphocytes (TILs) (Supplementary Table 3).