Complex sentence: 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.
Split into simpler sentences: In 1991, the founding members were incorporated back into the X-Men. However, "X-Factor" continued, focusing on a second X-Factor team, a U.S. government-sponsored team incorporating many secondary characters from the X-Men mythos.