The function of SPIDR (scaffold protein involved in DNA repair, Ensembl gene identifier ENSG00000164808) is as follows. Involved in early stages DNA double-strand break (DSB) repair via homologous recombination (HR) (PubMed:23509288, PubMed:23754376, PubMed:34253720, PubMed:39169038). As part of the Shu complex, promotes HR by regulating replication protein-A (RPA) dynamics on single- stranded DNA, thereby stabilizing RAD51 and DMC1 filaments on DNA (PubMed:34253720, PubMed:39169038). The Shu complex is essential during meiosis by stabilizing DMC1 filaments (PubMed:27967308, PubMed:34697795). In contrast, it is critical for only certain types of homologous-directed DNA repair, such as inter-homolog homologous recombination (IR-HR) (PubMed:34253720). IR-HR is a DNA repair mechanism where a cell repairs a DSB on one chromosome using the matching homologous chromosome as a template, rather than the sister chromatid (PubMed:34253720). {ECO:0000269|PubMed:23509288, ECO:0000269|PubMed:23754376, ECO:0000269|PubMed:27967308, ECO:0000269|PubMed:34253720, ECO:0000269|PubMed:34697795, ECO:0000269|PubMed:39169038}.