RNF4 and Fanconi anemia: This SUMO–RNF4 axis has been shown to generate the ubiquitinated products required for p97 extraction of Fanconi anemia ID complex components in response to DNA damage (Gibbs-Seymour et al., 2015) and to remove cytotoxic trapped PARP1 from chromatin (Krastev et al., 2022).