Can devpi proxy multiple remote respositories?

Our corp standard requires that all in-house build products (notably including .whl files) must be housed in Artifactory. We can resolve them from there via Artifactory's PyPi facade (read-only). But we don't want to have to check in external packages (from public PyPi) into Artifactory--and it makes no sense to do so. Can an index in devpi have, as a base, both public/pipi and an additional external, read-only repo, and serve as proxy for both?