Researchers proved that in a mouse pancreatic cancer model, DA inhibits the M2 polarization of tumour‐associated macrophages (TAMs) and activates DRD4, leading to a decrease in cAMP levels, and then inhibits the activation of the protein kinase A (PKA/p38) signalling pathway, thereby inhibiting the tumour‐promoting inflammatory effects of TAMs. This evidence concerns the gene DRD4 and neoplasm.