FIGURE 9: Tumor development and characterization in long-term DEN treated H19 knockout (H19 ko) compared to H19 wild-type (H19 wt) mice. (A) Tumor development in female (left) and male (right) DEN treated mice (female: H19 wt n=22, H19 ko n=25; male: H19 wt n=25, H19 ko n=20). (B) Predominant cell size in tumors of DEN treated female (left) and male (right) mice. (C) Representative immunohistological staining of proliferation marker Ki67 (left, score 0: no proliferating cells detectable; score 1: less than 1% proliferating cells with brown stained nuclei (arrow)) and expression of Ki67 in tumors of male DEN treated mice (right, H19 wt n=9, H19 ko n=10). (A-C) The p values were calculated by Chi-square test. * p < 0.05, ** p < 0.01, *** p < 0.001. (D) Igf2 expression in female (left) and male (right) control (co) and DEN treated (DEN) mice determined by qPCR (female: H19 wt co n=11, H19 ko co n=23, H19 wt DEN n=22, H19 ko DEN n=25; male H19 wt co n=13, H19 ko co n=18, H19 wt DEN n=25, H19 ko DEN n=20). The p values were calculated by Mann-Whitney U test. * p < 0.0125.