GFAP and neoplasm: Following 2nd (in case of GB8) or 3rd resection (in case of GB6 and GB9) not only the original mutational profile of analyzed cells was lost, as monitored by molecular analyses (mostly MLPA and Real-time PCR; Fig. 5h-i), but also the decrease in tumor-characteristic phenotype (loss of GFAP expression; Fig. 5d) was observed with the fraction of remaining proliferating cells (BrdU-positive; Fig. 5e).