From Asher v. Unarco Material Handling, Inc., 596 F.3d 313 (6th Cir. 2010):
The parties agree that the question of whether Rule 15(c) permits relation back of an amendment adding otherwise untimely plaintiffs and their claims to a timely-filed complaint is an issue of first impression for our circuit. Nevertheless, in urging Rule 15(c)'s ...
From Asher v. Unarco Material Handling, Inc., 596 F.3d 313 (6th Cir. 2010):
The parties agree that the question of whether Rule 15(c) permits relation back of an amendment adding otherwise untimely plaintiffs and their claims to a timely-filed complaint…