Expression of transcription factors in human fetal pancreas between weeks 7 and 21. (A) Expression analysis by quantitative real-time (qRT)-PCR of HLXB9, IPF1, PTF1A, PAX4, ARX, NGN3, INSM1, ISL1, NEUROD1, NKX6-1, NKX2-2, MAFB TCF2, FOXA2, FOXD3, and ONECUT1. (B) Immunostaining of 9-, 14-, and 21-week fetal pancreas using anti-insulin (green), anti-glucagon (red), and anti-IPF1 (blue) antibodies. Inserts show a higher magnification. (C) In situ hybridization analysis of the NGN3 spatial expression in 10-, 15-, and 22-week human fetal pancreas. Bar = 50 μm.