For MAP4K4, the upstream factor of MAPK signaling pathway, which is critical for KSHV reactivation, we also quantified the ORF50 copy numbers in MAP4K4 over expressed BC-3 cells; compared with the cells transfected with empty vectors, the ORF 50 copy numbers increased 3.51 fold after 48 hours of treatment (Fig 5B). Here, MAP4K4 is linked to breast cancer.