https://www.selleckchem.com/products/wnk-in-11.html Sarcoidosis is a systemic inflammatory disease of unknown etiology, pathologically characterized by non-caseating granulomas involving several organs and tissues. This pathological process can eventually affect the heart during his course leading to fibrosis associated with systolic dysfunction, conduction disturbance, and even sudden cardiac death. Due to this prognostic impact, diagnosis is crucial to optimize clinical management. The low sensitivity of endomyocardial biopsy and its invasive nature prevents its application as a first-line diagnostic approach. Thus, several efforts have been dedicated to the identification of advanced imaging tools for the diagnosis and monitoring of cardiac involvement in systemic sarcoidosis, including Positron Emission Tomography (PET). Starting from strengths and disadvantages of 18F-Fluorodeoxyglucose (18F-FDG) PET imaging, the present narrative review will summarize state of the art and future perspectives about radiotracers other than 18F-FDG of potential interest in the field of CS, including somatostatin receptor-ligands, proliferation markers and hypoxia displaying agents.Background Among the various orphan G protein-coupled receptors, apelin receptor (APJ), originally identified in the human genome as an orphan G-protein-coupled receptor, was deorphanised in 1998 with the discovery of its endogenous ligand, apelin. Apelin and APJ mRNA are widely expressed in peripheral tissues and the central nervous system in mammals. Objective In this review, we discuss the characteristics, pharmacology, physiology, and pathology of the apelin/APJ system in mammals. Conclusion Several physiological roles of the apelin/APJ system have been reported, including in homeostasis, cardiovascular maintenance, angiogenesis, and neuroprotection. In cellular signaling, apelin has been shown to drive the PI3K/Akt, MAPK, and PKA signaling pathways, leading to cell proliferation and protection from