TP53 and neoplasm: While it might be argued that in the tumour tissue samples analysed, all P2-derived transcripts originated from the normal cells (i.e., endothelial cells, pericytes, macrophages and so on) present, the P2 transcripts from the Tp256MG line and the GB166X1 xenograft (no wild-type TP53 and use of human specific primers) could only have originated from the tumour cells.