ZAP70 and neoplasm: Continuous stimulation of nor‐adrenaline in the tumor microenvironment triggers the canonical pathway of β2‐ARs expressed in T lymphocytes.[90] β2‐AR triggers a cascade involving G protein dissociation, Cyclic Adenosine Monophosphate (cAMP) production, and Protein Kinase A (PKA) activation, which subsequently modulates key signaling molecules like Lck and ZAP70.