The phrase "important regulator" refers to someone or something that has the power to control or direct certain activities in a significant way. Full definition
Insulin is the single most important regulator of fat metabolism in the body. (chestsculpting.com)
These alternative products may function as important regulators for the processing of nutrients. (sciencedaily.com)
So leptin is not the only important regulator, the fact of leptin is actually integrated with a number of other signals, so this is what I wanted to highlight in this slide. (abcam.com)