To study NP extravasation from the leaky tumor vasculature and accumulation in tumor tissues, Wang and collaborators [89] set up a microfluidic tumor-vasculature-on-a-chip consisting of channels lined with human endothelial cells made permeable with tumor necrosis factor and surrounded by 3D spheroids immersed in a dense extracellular matrix. This evidence concerns the gene TNF and neoplasm.