Removal of Nrf2 exacerbates compensatory erythroid hyperplasia in Trsp-deficient mice. (A) Macroscopic appearance of spleens at 4 weeks after the final pI-pC injection. (B) Spleen/body weight ratios of Nrf2+/+:Trspfl/del (n = 7), Nrf2+/+:Trspfl/del:Mx1-Cre (n = 7), Nrf2–/–:Trspfl/del (n = 8), and Nrf2–/–:Trspfl/del::Mx1-Cre (n = 10; *P < .001). (C-J) Histopathological examination of spleens at 4 weeks after the final pI-pC injection. Scale bars correspond to 500 μm (C-F) and 25 μm (G-J), respectively. (K) Serum erythropoietin levels were determined at 4 weeks after final pI-pC injection. Horizontal lines represent average values in each genotype (*P < .05; **P < .001).