Type III secretion: what's in a name?

The term ‘type III secretion’ has seen widespread use. However, problems persist in nomenclature. We propose that the standard abbreviation for this kind of secretion should be ‘T3S’ and that ‘type III secretion system’ should be abbreviated to ‘T3SS’. There is also a need for a new terminology to distinguish flagellar and non-flagellar type III secretion systems that reflects their common evolutionary ancestry but does not obscure their distinctive features. Finally, the use of the term ‘type III secretion’ to cover cytolysin-mediated translocation is to be deprecated because an authentic type III secretion system has already been described in Gram-positive bacteria, namely the flagellar protein export apparatus.