Metformin's clinical relevance may be due to reduced hepatic glucose output, lower insulin, and consequently lower IGF-1, which are all favorable for cancer.

“is that working because hepatic glucose output is going down and insulin is going down and presumably IGF is going down”

“So I approached it as a cancer drug from that perspective, but the more conferences we go to, there's a plethora of data coming out of metformin and a lot of people are studying it from the perspective of impaired complex I or complex II activity in the mitochondria.”