FIG. 4.

Insulin secretion from islets isolated from Sox4 Y123C mutant (black diagonal stripe bars), insulin receptor heterozygotes (black bars), and wild-type littermates (white bars) in response to glucose (0, 2, or 20 mmol/l) or 200 μmol/l tolbutamide (tol) normalized to total insulin content. Islets were isolated from five mice of each genotype. The data represent the mean of five animals (with three technical replicates per animal and each replicate comprising five islets ± SE). Statistical analysis by Student's t test, where *P < 0.05 and **P < 0.01.