Department of Biochemistry, University of Kuopio, Kuopio, Finland. olavi.kajander@uku.fi
Nanobacteria, also known as calcifying nanoparticles (CNP), are controversial infectious agents not matching the current criteria for 'living organism'. Despite the controversy of their classification, they propagate and cause cell death in vitro and are associated or found in many human diseases. Thus, more efforts should be focussed on research on pathogenicity of CNP.