Redox is a phenomenon witnessed throughout the natural world and is the starting point for creating and maintaining the energy of life. The redox balance regulates energy generation and physiological activities, such as cell signaling, gene transcription, apoptosis, cellular aging, and the aging of the whole organism.

While 90% of the inhaled oxygen is used to generate energy in the electron transport chain (ETC) of mitochondria, 4-5% is used to create reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), superoxide (O2-), and hydroxyl radical (OH-).

If reactive oxygen generated by energy production or signaling substances is not sufficiently removed, reactive oxygen that has lost electrons due to oxidation often takes electrons from proteins in our body and attacks DNA and cellular components, causing damage to cells or severely damaging cellular structures such as cell death. Therefore, a balance between prooxidants and antioxidants is essential for organisms that use oxygen.

However, when prooxidants dominate and disrupt the balance, cells are damaged by increased reactive oxygen. This state is called oxidative stress.

Based on 'molecular medicine' advocated by Linus Pauling, the father of functional medicine, who won the Nobel Prize in Chemistry in 1954 and the Nobel Peace Prize in 1962, a series of studies performed quantification of specific VOCs found in human respiration. As analysis technology progresses, the potential as 'biomarkers' of VOCs contained in respiration becomes more conceivable, and the number of related papers and publications has recently multiplied.

Owlstone Medical, established in Cambridge, the UK, in 2004, announced Breath Biopsy through respiration analysis, and the development of non-invasive biomarkers through respiration is drawing attention.

As a result of literature analysis of papers published in more than 4,800 medical journals worldwide, it was concluded that the analysis of volatile organic substances (VOCs) could serve as a new biomarker.

We systematically structured and analyzed these results after identifying more than 50 research papers examining VOCs likely to serve as biomarkers for lung cancer in human respiration.

Through this, we identified VOCs expressing significant changes in respiration of cancer patients, unlike healthy people, among more than 1,000 different VOCs. In a recent study conducted in Taiwan, significant changes were detected in a total of 116 VOCs, and 77 VOCs were commonly found in many studies over the years. According to the structural analysis results of all these studies, we selected specific VOCs that were judged to be most suitable for diagnosing lung cancer.