The heterotetrameric GINS complex is essential for the establishment of DNA replication forks and replisome progression in eukaryotes. GINS is one of the core components of the replicative helicase, the CMG (Cdc45-MCM-GINS) complex, activating the helicase activity of MCM to unwind duplex DNA ahead of the moving replication fork. Eukaryotic GINS also links with other key proteins at the fork to maintain an active replisome progression complex. (Adapted from PMID:22918584 and PMID:20070258.)