IDO1 and non-small cell lung carcinoma: A comparison between the 3 epithelial (E) NSCLC cell lines (H441, 322 M, HCC4006) and the 3 mesenchymal NSCLC cell lines (H1299, H460, H549) showed a significantly higher level of IFN-γ stimulated IDO-1 mRNA induction in the second group (Fig. 3A).