Furthermore, within the interface of the untreated PDOX (Additional file 1: Fig. S17a), we observed proliferating (MKI67-positive) tumour cells in close proximity to Cd68-expressing tumour-associated microglia and Gfap-expressing astrocytes (Additional file 1: Fig. S17b), similar to drug-treated PDOX. Here, CD68 is linked to neoplasm.