ACE and heart failure: Indeed, two of the most prognostically important medications in treating heart failure target GPCRs and their pathways: (1) beta-adrenergic (β-AR) pathway blockers and (2) angiotensin converting enzyme (ACE) inhibitors/Angiotensin II receptor type 1 blockers (Kober et al., 1995; Salazar et al., 2007; Hunt et al., 2009; McMurray et al., 2012).