ADRB2 and cancer: Previous evidence has shown that activation of β-adrenergic receptors, particularly β2-adrenergic receptor (β2-AR), contributes to cancer development (Chida et al, 2008; Dhabhar et al, 2012; Hara et al, 2011; Saul et al, 2005; Sood et al, 2006; Spiegel et al, 2007; Yang et al, 2002; Yang and Eubank, 2013) and leads to reduced antitumor immunity (Qiao et al, 2019).