How the virophage compels the need to readdress the classification of microbes

•Mimivirus challenges the size definition of viruses.•The virophage is a virus that infects giant viruses.•The life and size of the giant virus challenges the classification of microbes.

The discovery of Mimivirus opened the door to reclassifying viruses and microorganisms. Because the definition of a virus had been based on their putative small size, giant viruses have been widely neglected, as have their own viral parasites: the virophage. Current studies show that giant viruses can be found worldwide in the soil, water, animals and humans.Their existence forces us to create new classifications, the most recent being TRUC, to accommodate the existence of four branches of microorganisms, i.e., bacteria, archaea, eukaryotes and giant viruses.