MAPK8 and osteosarcoma: Figure 4(b) reveals that DBT had a dose-dependent effect on the expression of MARKs such as p-ERK (about 42 and 44 kDa) and p-JNK (about 49 and 55 kDa). 1,000 μg/mL of DBT induced the highest p-ERK expression and higher p-JNK levels. No effects occurred at lower doses, while some declined at higher concentrations. Moreover, the decrease in p-38 phosphorylation was found as p-ERK and p-JNK activity increased. We believe that DBT can activate the phosphorylation of p-ERK and p-JNK signal pathway to stimulate the proliferation and differentiation of human osteosarcoma cell line MG-63.