X-Factor is an American comic book series published by Marvel Comics. It is a spin-off from the popular X-Men franchise, featuring characters from X-Men stories. The series has been relaunched several times with different team rosters, most recently in X-Factor v. 3 as X-Factor Investigations.
X-Factor launched in 1986, featuring an eponymous team composed of the five original X-Men. In 1991, the founding members were incorporated back into the regular X-Men series, and X-Factor relaunched as a U.S. government-sponsored team incorporating many secondary characters from the X-Men mythos. The series was canceled in 1998.
In 2002 a four-part X-Factor mini-series detailed an investigation by the Mutant Civil Rights Task Force into an alleged conspiracy by hate-groups to commit murder against mutants. The series was written by Jeff Jensen with artwork by Arthur Ranson.
In January 2006 a new X-Factor series was launched, following the mutant detective agency X-Factor Investigations. The series drew controversy for establishing a homosexual romantic relationship between Rictor and Shatterstar, a move criticized by Shatterstar's co-creator, Rob Liefeld. The 2005 series was numbered from issue # 1 - 50, and then they amalgamated the numbering of the two series. They took the first 149 issues from the first series, added the 50 from the second series and then continued the numbering at 200. The series ended in 2013 at issue # 262.
In 2014 a new series written by David, All-New X-Factor was launched featuring a new corporate-sponsored X-Factor team.