Primary hepatocytes were isolated from 12-week-old male Prom1+/+ (WT) or Prom1-/- (KO) mice, serum-starved and stimulated with glucagon. H. The nuclear localization of p-CREB 10 minutes after glucagon stimulation (10 nM) was determined by immunofluorescence staining. Scale bar, 20 μm. 