Besides, Campbell and colleagues reported that metformin users also had reduced cancer compared to non-diabetics (RR 0.94, 95% CI 0.92–0.97) and CVD compared to diabetics receiving non-metformin therapies (HR 0.76, 95% CI 0.66–0.87) or insulin (HR = 0.78, 95% CI 0.73–0.83). Here, INS is linked to cancer.