DRD4 and central nervous system cancer: For example, DA activation of DRD4 in pancreatic cancer leads to a reduction in cAMP, subsequently inhibiting the activation of the PKA/p38 signaling pathway, thereby suppressing tumor‐associated macrophage‐mediated pro‐tumorigenic inflammation.[34] Additionally, in pediatric central nervous system tumors the histone methyltransferase the enhancer of zeste homolog 2 inhibits DRD4 expression through enhancing the methylation of DRD4 promoter.[35] Nevertheless, the underlying molecular mechanisms of DRD4 in tumor progression remains unclear.