MDK and cancer: The network centrality analysis of the PARs pathway showed that Malignant Cluster01 was the main source of PARs ligands targeting the Tip-like EC subpopulation in malignant tumor cells, indicating that the main pathway through PARs interaction was paracrine, as shown in Fig. 6D. MDK - (ITGA6+ITGB1) had the greatest contribution to this pathway (Fig. 6E).