Histopathology of H&E-stained tissue samples. Magnification is 20× except for the second row that was prepared with Gömöri staining to visualize reticulin fibers (magnification, 40×). The mice were killed at 28-30 weeks of age (controls and VavCre;FF1) or 28-30 weeks after induction with pIpC (MxCre;FF1) or tamoxifen (SclCre;FF1). Because of the markedly reduced likelihood of survival, SclCre;FF1;Jak2^fl/fl mice were killed 14 weeks after induction with tamoxifen.