Meanings of established roles in English

Like perfringolysin O, the toxins with established roles in intestinal disease form membrane pores.

So currently, we have something like 13 established roles in Afghanistan and something like four contractors.

Summary: Recent studies have established roles for the RORs in physiological development and the advent of disease.

Linker histones are DNA packaging proteins with established roles in chromatin compaction, gene transcription, and in homologous recombination (HR)-mediated DNA repair.

The liver X receptors (LXRs) are ligand-activated nuclear receptors with established roles in the maintenance of lipid homeostasis in multiple tissues.

But years ago I went to a not dissimilar event on a Scottish estate, and the whole point was the annual blurring of established roles.