23andMe Inc. will participate in an early mediation on Jan. 31 to resolve more than 35 class actions brought over its data breach, but not all plaintiffs’ lawyers are on board.

The mediation, to be held at a Westin hotel in Napa, California, will include most of the plaintiffs’ firms that have filed cases. But Chicago’s Edelson, in a filing ahead of the planned talks, said the mediation was “bound to be inefficient” or, at worst, result in a “sell-out settlement.”