Effects of radon inhalation on the influence of 20 mg/kg CDDP administration on A) the serum creatinine level, and B) antioxidant-related substances in C57BL/6J and BALB/c mice with CDDP-induced renal injury. $P < 0.05 and $$$P < 0.001 indicate the treatment groups vs. the control in the C57BL/6J strain. The sham group represents the group administered with 20 mg/kg CDDP only with air inhalation. #P < 0.05, ## P < 0.01, and ### P < 0.001 indicate the treatment groups vs. the control in the BALB/c strain. +P < 0.05 and +++P < 0.001 indicate the radon inhalation groups vs. the sham in the BALB/c strain.