Ace, short for Angiotensin converting enzyme, is a zinc-dependent dipeptidyl carboxypeptidase. It is a key component of the renin-angiotensin-aldosterone system (RAAS), which is crucial for blood pressure homeostasis. ACE generates the vasoconstrictor peptide angiotensin II, and also degrades biologically-active peptides like bradykinin [3,4,6].

ACE inhibitors, which target Ace, are commonly used medications. A dry cough is the most common adverse effect of ACE inhibitors, possibly due to suppression of kininase II activity and subsequent accumulation of kinins, substance P, and prostaglandins. This cough is a class effect and may occur months after starting therapy [1].

In the context of COVID-19, the relative deficiency of ACE2 (a related enzyme) during infection could be linked to clinical features like ARDS and coagulation abnormalities, highlighting the importance of the ACE-related pathway in disease pathophysiology [2].

In lung and prostate cancer, primary tumor growth leads to a decrease in ACE activity in the respective tissues, and ACE phenotyping shows potential for early cancer diagnosis [5,7]. Elevated ACE expression in tissues (reflected by blood ACE levels) is associated with increased risk of cardiovascular diseases and is a marker for granulomatous diseases, and ACE phenotyping can non-invasively detect patients with systemic sarcoidosis [8].

In conclusion, Ace is essential for regulating blood pressure through its role in the RAAS. Studies on Ace, especially those related to the effects of ACE inhibitors, have provided insights into various disease areas such as cough associated with drug use, COVID-19 pathophysiology, cancer, cardiovascular diseases, and granulomatous diseases. These findings help in understanding disease mechanisms and potentially developing better treatment strategies.