Figure 1 .

Histologic analysis of X-ray–irradiated mouse small intestine. A) Representative sections immunohistochemically stained for P-Stat3 in small intestine of control WT and irradiated WT and irradiated Stat3^ΔIEC mice. Scale bars, 100 μm. Insets indicate enlarged images of boxed areas. B) Survival rate of WT and Stat3^ΔIEC mice after X-ray irradiation (n = 9 for WT and n = 12 for Stat3^∆IEC mice). C) Representative histology sections from WT (left) and Stat3^ΔIEC (right) mouse intestines (H&E) (top) and immunohistochemical staining for Ki-67 (middle) and CD44 (bottom). Insets show enlarged image views of boxed areas. Scale bars, 100 μm. D) Number of crypts in microscopy fields (left) and Ki-67–positive cells per crypt (right) are shown (means ± sd). *P < 0.05.