ADRB2 and neoplasm: β-ARs are expressed on the membranes of various tumor cells and tumor-related cells, such as immune cells, fibroblast, and epithelial cells, and epithelial cells, and two of the three subtypes of β-ARs, including β2-AR and β3-AR, take part in tumorous β-signaling (Daly and McGrath, 2011; Calvani et al., 2020).