In the supernatant from wt control HeLa cells, we could not detect any tryptophan after 24 hr of IDO1 induction as expected; by contrast, in the same samples, we detected 45 ± 2 μM of KYN; this concentration is consistent with previous observation of KYN concentrations at ~37 μM in a tumor model (Opitz et al., 2011) (Figure 3G, Table S1). This evidence concerns the gene IDO1 and neoplasm.