FBXO5 and neoplasm: Although E1-E933A deposition in the mammary tissue was very similar to the one of EMI1 WT (Fig. 6a), the evaluation of tumor onset by palpation showed that appearance of palpable tumor masses in Δ16HER2/EMI1 KOtg mice was completely overlapping with the one Δ16HER2/EMI1 KO animals (13.27 vs 13.32 weeks) (Fig. 6b), clearly indicating that the gC1q domain and, thus, EMI1 binding to integrins, was a critical event in regulating the tumor onset of Δ16HER2 transgenic mice.