IGF1 and type 2 diabetes mellitus: Our findings relating loss of function variants in GIGYF1 to metabolic and anthropometric outcomes are broadly consistent with the notion that in individuals carrying two functional copies of this gene, GIGYF1 enhances insulin and IGF-1 receptor signaling, leading to greater handgrip strength (relative to loss of function carriers), sitting height and circulating IGF-1 levels (due to increased insulin signaling), and lower % body fat, WHR, HbA1c, glucose levels, and susceptibility to T2D.