Procalcitonin (PCT) is a peptide precursor of calcitonin, nowadays it has emerged as akey biomarker in the detection of bacterial infections.A recent study has investigated the potential role of procalcitonin in non-infectious diseases. While its major application is in infection detection, greater PCT levels have been observed in various inflammatory conditions, including acute pancreatitis, trauma, and post-surgical inflammation. The thyroid gland C-cells produce the majority of procalcitonin. However, during infections, particularly those caused by bacteria, different tissues and organs, create more procalcitonin. Pro-inflammatory cytokines are responsible for this increase in response to bacterial endotoxins like lipopolysaccharides (LPS). In contrast, viral infections decrease procalcitonin synthesis via interferon-gamma, making PCT a helpful tool for distinguishing between bacterial and viral infections.Procalcitonin is proteolytically cleaved to generate calcitonin; however, during infection, the cleavage is partial, and procalcitonin is released into the bloodstream. PCT levels can rise dramatically within 2-6 hours of illness initiation and peak between 12-24 hours, making it an early indicator of systemic bacterial infection.Procalcitonin is also used as a diagnostic tool, and as a prognostic marker to measure mortality risk and the efficacy of treatment interventions. PCT levels can rise in non-infectious inflammatory disorders, leading to false positives. For example, patients who have recently undergone surgery, trauma, or significant burns may have elevated PCT levels due to systemic inflammation rather than bacterial infection. Furthermore, immunosuppressed patients, such as those receiving chemotherapy or with advanced Human Immunodeficiency Virus (HIV), may have reduced PCT responses even amid severe co-infections.More research is needed to determine how PCT can be included in the care of various non-infectious illnesses and whether it can provide prognostic information in these situations.