For example, the fluid flow was found to enhance glioma cell migration via a CXCL12–CXCR4 signaling-dependent mechanism in both 3D in vitro models using invasive cells (RT2, rat astrocytoma; U87MG, human glioblastoma; C6, rat astrocytoma) in a HA/collagen I matrix and in vivo models such as rats [99]. The gene discussed is CXCL12; the disease is glioma.