Since upregulation of IFN-γ production is one of the key mechanisms in tumor regression, we monitored the levels of IFN-γ levels in PDAC tumors by double-labeling tumor tissues with IFNγ and CA19-9 (Figure 8D), a commonly used PDAC diagnostic marker used to detect pancreatic cancer treatment [39]. The gene discussed is IFNG; the disease is pancreatic neoplasm.