IFNG and colorectal cancer: Next, we generated 40 additional knock-in lines using base editing to install mutations in other IFN-γ pathway genes in HT-29, and a primary MSI colorectal cancer tumor organoid, CRC-9 (harboring FBXW7 and TP53 driver mutations), and used flow cytometry to assess the induction of MHC-I and PD-L1 expression upon stimulation with IFN-γ (Figure 5C).