GFAP and neoplasm: Most importantly, the expression of MHCII was low or undetectable in GFAP-expressing areas, and conversely, GFAP+ cells were not detected in MHCII-rich areas, showing mutually exclusive regions with no clear overlap and differentiating the tumor nest from the stroma (Fig. 8a and b and Additional file 12: Supplementary Video 5).