FBXO5 and triple-negative breast carcinoma: Work by Marzio et al. showed that EMI1/FBXO5 constitutively controls ubiquitin-mediated degradation of RAD51 and suggested that a subset of BRCA1-deficient triple-negative breast cancer (TNBC) cells develop resistance to PARPi due to reduced levels of EMI1/FBXO5, causing accumulation of RAD51 and consequently restoring HR (232).