The process of homologous recombination is a major DNA repair pathway that operates on DNA double-strand breaks to promote error-free repair. Human Rad51 protein assembles on a DNA molecule through cooperative binding and forms a long filament for homologous recombination. In addition to Rad51 protein, five paralogs have been identified in vertebrates, Rad51B, Rad51C, Rad51D, Xrcc2 and Xrcc3. Rad51C binds single- and double-stranded DNA and preferentially binds 3'-end-tailed double-stranded DNA. Rad51C is expressed in a variety of tissues, with highest expression in testis, heart muscle, spleen and prostate.