However, in the culture course GB cells maintained in monolayer begin to lose tumor characteristics and there is an increased number of proliferating normal cells when compared to cancer cells, while single remaining GFAP-positive cells are not undergoing mitoses (p < 0.005 for GB6, p < 0.003 for GB7, p < 0.011 for GB8 and p < 0.013 for GB9 cultures; Additional file 4: Table S4). Here, GFAP is linked to neoplasm.