IFNB1 and colorectal carcinoma: Notably, Colo-205 colorectal carcinoma cells co-cultured with MSCs modified with CDUPRT-IFNb at a ratio of 1 MSCs to 200 cancer cells (0.5% engineered MSCs) showed a killing efficiency of approximately 60%, double the percentage of killing of cells modified with CDUPRT alone (p < 0.05, Fig. 4A).