In triggering cancer cell reactivation after dormancy, the important players are: endothelial cells from neovasculature that produce TGF-β1 and periostin [73]; adipocytes via FABP4 [74]; macrophages with cathepsin K [75]; and protein in the microenvironment, such as type 1 collagen [76] and fibronectin [77]. Here, POSTN is linked to cancer.