Moreover, in a recent study, Qi et al. showed that in the tumor microenvironment of stomach adenocarcinoma, there is an increased concentration of norepinephrine and a slight increase in beta 3 adrenoreceptors, but predominantly an increase in beta 2 adrenoreceptors and the absence of expression of beta 1 adrenoreceptors [38]. The gene discussed is ADRB2; the disease is gastric adenocarcinoma.