Oral sores (aphthas) are a common and bothersome phenomenon caused by wounding the mucosa while chewing, biting the cheek or tongue, dental treatment etc. Oral sores (aphthas) also appear against the background of various viral diseases, especially herpes. RAS disease (recurring aphthas), suffered by about 10% of Israelis, causes frequent and repeated oral ulcers. The treatments today are solely symptomatic, some of which cause severe side-effects, sometimes more serious than the phenomenon itself.