PCNA protects arrested forks from collapse and promotes replication traverse of DNA interstrand crosslinks (ICL) by recruiting FAN1 (Fanconi-associated nuclease 1) and FANCM (Fanconi anemia group M protein) as an activator of the Fanconi anemia pathway [9,10], promotes ICL repair by recruiting the nuclease SNM1A (DNA cross-link repair 1A protein) [11], and facilitates replication fork reversal required for fork restart by recruiting the translocase ZRANB3 (zinc finger RANBP2-type containing 3) [12,13] (Figure 2). Here, FAN1 is linked to Fanconi anemia.