Klb expression in the SCN is required for FGF21 suppression of growth and insulin, and stimulation of glucocorticoid activity. (a – d) Male mice of indicated genotypes without (–) or with (Tg21) the Tg(Fgf21). (e – i) Male mice of indicated genotypes implanted with osmotic mini-pumps delivering vehicle (V) or human FGF21. Animals were sacrificed at ZT8 (a, c), ZT3 (e – i), or at ZT0 (b, d), and body weight, plasma hormone levels, and liver gene expression were determined. Data represent mean ± SEM, n = 5–9 for (a – d) and n = 6 for (e – i). Ct values shown inside bars. Asterisks indicate significant differences (P < 0.05) compared to (–) or (V) controls, or as indicated.