Serum levels of selected cytokines in immunocompetent rats implanted with GBM xenografts.

Shown are the serum concentrations of cytokines that were consistently detected throughout the time course of the experiment. X axis indicates days from implantation (d = 0). The lines show average serum concentrations (± SEM) in the rejection group (black squares) vs. the engraftment group (open circles) of rats implanted with high generation P3 spheroids. Significant differences are denoted by asterisks (*** marks P<0.001, * marks P<0.05).