Plasma is a partially or fully ionized gaseous state of matter containing chemically active species, such as ions, electrons, photons, reactive oxygen and nitrogen species, and UV light. Cold atmospheric plasma (CAP) can be applied onto vital, heat-sensitive surfaces and is currently used in surgery, endoscopic procedures, and wound care with proven antimicrobial efficacy and the ability to deactivate pathogens, stop bleeding and stimulate cell proliferation 1 2. Recent pre-clinical observations suggested an anti-tumoral potential, for example in melanoma, glioma and colorectal carcinoma cells 3 4. This article is protected by copyright. All rights reserved.