It is recognized that tumors do not exist and grow as isolated entities of neoplastic cells, but
rather in continuous and bidirectional communication with adjacent stromal cells. Stromal
cellular components, like fibroblasts, endothelial cells and multiple immune cells, have been
proven to play critical roles in tumor development. In the past decade, a variety of in vitro
three-dimensional (3D) tumor models were developed to replace conventional monolayer
cell culture systems. 3D cell coculture between tumor and stromal cells has also gained …