ADRB2 and metastatic malignant neoplasm: Based on our findings that adrenergic agonists stimulated the metastatic ability of cancer cells via the β2-AR/Src axis [26], which was completely abrogated by EPF treatment, the concept of moving Qi could mean suppression of excessive activation of the β2-AR/Src/EMT axis in chronic stress-induced metastatic cancer.