Since immunotherapy has been recently rapidly developing as a therapeutic renaissance in PAAD, we aimed to determine whether BDNF expression was associated with immune checkpoints and discovered that high BDNF mRNA levels were strongly associated with high expression of CD274, PDCD1, CTLA4, BTLA, CD276, HAVCR2, IDO1, LAG3, TIGIT, and NRP1 (Figure 8(b)). This evidence concerns the gene IDO1 and pancreatic adenocarcinoma.