This pathway is giving a summary of currently known nanoparticle effects on cells and organisms. Although there is currently no nanoparticle-specific effect known, there is a cascade of effects triggered if cells or organisms are exposed to nanoparticles: The most abundantly observed event is oxidative stress which causes DNA damage, protein and lipid oxidation, and cell death. The mere overload of nanoparticles in the vesicular system leads to cytoskeleton and cell adhesion problems and interfere with the cell's autophagic system. Some specific nanoparticles are reported to interfere with the cell membrane, others stimulate the blood coagulation system. The release of metal ions from specific nanoparticles challenges the metal disposal system of the cell.