In addition, expression of tumour-associated key cytokine/chemokines, such as interleukin-6, interleukin- 8 and CXCR-4, matrix degrading enzyme matrix metallopeptidase 9 (MMP-9) and cancer stem cell markers like CD44 and ALDH1 observed in the parent HNSCC tumours were also preserved in the CANScript tumour ecosystem (Supplementary Fig. 7a–c). This evidence concerns the gene CXCR4 and cancer.