Foxp1/2/4 cKO mice have dramatically reduced islet alpha cell mass. (a–f) Immunohistochemical analysis of glucagon (a, d), insulin (b, e) and somatostatin (c, f) of 4W control and Foxp1/2/4 cKO pancreases. Scale bars, 40 µm. (g–i) Alpha (g), beta (h) and delta (i) cell mass was obtained from 4W control and Foxp1/2/4 cKO pancreases (n=3 mice per genotype; six slides per hormone per mouse were analysed). *p<0.05 and ***p<0.001 after two-tailed Student’s t test