RAD51 and breast cancer: Mutation of at least one of four T. brucei RAD51 paralogues also impairs switching [30] (R Dobson et al., unpublished), as does mutation of the T. brucei orthologue of BRCA2 [31•], a breast cancer oncogene that co-ordinates loading of RAD51 onto processed DNA double strand breaks (DSBs) [28].