Numerous worldwide research groups are investigating the possibility of non-invasive VOC detection in the exhaled air, enabling the diagnosis of various systemic diseases6, including carcinomas (lung, breast and colorectal), tuberculosis, kidney failure and asthma. The VOCs in question are alkanes (C4-C20), methyl-alkenes and benzene derivatives, found in healthy individuals in concentrations of 1-20ppb (part per billion), while in disease, the concentration of disease-specific VOCs is increased. VOCs are suggested to be produced by the distressed tissue due to oxidative stress, by the liver as part of a metabolic reaction, or by the immune system.