Possible roles of GINS during DNA replication. A. Structural component of the CMG complex that contains DNA helicase activity. Cdc45 protein is represented in red, Mcm2–7 proteins in orange, and GINS as a blue ring. B. DNA polymerase ε auxiliary factor. The different subunits of Pol ε are depicted in yellow. The relative position of the different components in each protein complex is speculative. See text for details.