We reached out to AACR nearly two years ago when we brought on board Cellosaurus because cancer journals use a lot of cell lines, in addition to mice and antibodies. The use of RRIDs was compelling and it seemed everything was on track to move AACR towards requiring RRIDs.

It is with great pleasure that I report that AACR will support RRIDs:
http://aacrjournals.org/improv-reprod

If the use case is compelling and the idea is simple, why does it take so long to start working with a journal, or in this case a group of journals?

Turns out that it is not simple to change editorial policy at a journal. The boards, both editorial boards and often the society need to weigh in on decisions and they only meet a few times a year.
 
Next steps: Are we done now that this announcement is made?

Unfortunately, when policy is agreed upon and established, the measured adherence rate to the new policy is around 1%. Therefore, our job is not done because the staff now need to be convinced that this editorial decision is something they should pay attention to in their daily tasks.

Each journal is on a spectrum of policy enforcement, outlined by the TOP guideline levels and there are many steps between the instructions to authors and requiring that authors comply.

We look forward to seeing RRIDs in AACR journals in the next few months.