Figure 3. Induction of DSBs during the recovery of cyclin D1-mediated aberrant replication forks. PCNA, a clamp loader, is involved in the formation of the replication fork complex and regulates replication fork progression. Cyclin D1 binding to PCNA in a replication fork complex inhibits replication fork progression. Mus81 creates DSBs at a replication site to remove aberrant replication forks for the recovery from replication stress mediated by cyclin D1 overexpression. Replication forks are then reconstructed to resume DNA replication.