In stark contrast, a significant tumor growth delay was seen with the combination of IR and anti-CTLA4 (p < 0.0001; median days to endpoint: anti-CTLA4 6.5 days, 16 Gy + anti-CTLA4 47.5 days) compared to IR and isotype control (p < 0.0001; median days to endpoint: IgG 9 days, 16 Gy + IgG 31 days; Figure 4c). This evidence concerns the gene CTLA4 and neoplasm.