Mystique's Brotherhood of Mutants/Freedom Force

3rd lineup (BoEM)
This team unsuccessfully attempted to assassinate anti-mutant Presidential candidate, Senator Robert Kelly. Tired of being hunted as criminals, Mystique offered the service of the team as a government strike force, Freedom Force in exchange for a pardon. Freedom Force was disbanded after a botched mission in the Middle East. 

Excalibur (1987-1998, 2004-2005, 2005-2007)

Excalibur vol. 1

[1987 - 1998]

Excalibur was a superhero team based in in the United Kingdom. It contained several former members of the X-Men and it offshoots.

The 198 members (2006 - 2007)

"The 198" largely refers to the group of mutants living within the grounds of the Xavier Institute but are not members of the X-Men, Institute staff members or members of the Institute student body.