TGFB2 and brain cancer: However, in response to brain injury, stroke, or brain cancer pathologic conditions, astrocytes become activated, a process named reactive gliosis, which is associated with profound changes in gene expression.29–32 Although astrocytes also tend to be very reactive in cell culture,33 astrocyte activity is a highly heterogeneous state depending on the specific injury.34 Thus, whether TNBC cells affect the TGF-β2 expression by astrocytes was examined.