MAPK3 and breast cancer: Further investigations into the anti-tumor mechanism of action revealed that DNP could downregulate the expression of COX-2 and PD-L1, inhibit prostaglandin secretion, reduce the expression of the breast cancer-related protein BRD4 and the phosphorylation of extracellular signal-regulated proteins 1/2 (ERK1/2), and block the expression of the breast cancer cell oncogene c-Myc (Figure 7C).