Having shown that MAP4K4-dependent signalling pathways are involved in the increased invasiveness of KSHV-infected primary and immortalized endothelial cells, we could demonstrate that MAP4K4 is highly expressed in the pathognomonic KSHV-infected endothelial spindle cells in KS lesions (figure 8A–D), suggesting that it may indeed play a role in vivo in aspects of KSHV-induced pathogenesis. Here, MAP4K4 is linked to Kaposi's sarcoma.