MAPK8 and osteoporosis: The protein level of ERK1/2 and p-ERK1/2 was significantly improved by the treatment with 125 and I-9 in both femur and liver tissue; however, the p38 and JNK protein levels were not increased in the femur or liver tissues of aged mice treated with 125 or I-9, indicating that the ERK signaling pathway may be associated with the function of 125 and I-9 in osteoporosis (Figure 5F,G).