DPP4 and breast cancer: They reported that the influence of DPP-4 inhibitors on the risk of breast cancer was not significant in the results of randomized controlled trials (RR = 0.74, 95% CI: 0.36–1.52), but that in the results of observational analysis, such risk is decreased (HR = 0.76, 95% CI: 0.60–0.96) [80].