One of the S.G.C. units that operate out of Cheyenne Mountain. When Russia pressured the S.G.C. for greater involvement in the Stargate program General George Hammond converted SG-4 into an exclusively-Russian team.
Members of SG-4 include (or have included) Sergei Evanov.
Fire and Water - When mineral scans from P8X-362 are good, General Hammond orders the unit back to the planet.
Singularity - SG-4 is assigned to return Cassandra to Hanka, along with Major Carter, but the mission is halted when Cassandra nears the Stargate, activating the explosive in her body and engaging a count-down.
Metamorphosis - SG-4 returns from P3X-367 with Alebran, an inhabitant who says the Goa'uld Nirrti has destroyed his village.
Lifeboat - SG-4 assists in the relocation of the survivors of Talthus.