Null mice die around embryonic day 11 and exhibit abnormal angiogenesis. Defects are observed in branchial arches and there is remarkably impaired vascular development of embryos and yolk sacs. Exogeneous VEGF on FOX1-deficient endothelial cells show markedly different morphological response. Active osteocalcin/BGLAP as well as serum insulin and beta-cell and gonadal fat levels were increased, but there is no change in total fat content, lean mass, and body weight. Effect on RUNX2 activity was inhibited. FOXO1/ATF4 double happlo-insufficient mice exhibit also an increase in insulin levels and beta cell proliferation, but there is an increase in insulin sensitivity demonstrated by an increase in expression of insulin-sensitizing hormone adiponectin. Gonadal fat levels and adipocyte numbers were decreased. Osteocalcin/BGLAP levels were unchanged.