AQP4 and glioblastoma: Interestingly, the analysis revealed that cells (N = 104) with a high 5ALA + signature also expressed a high level of the cancer mesenchymal marker CD44, while almost half the CD44 expressing cells (N = 64) also expressed the truncated radial glial marker AQP4. We further validated CD44 gene expression across patient-matched spatially distinct GBM regions and 5ALA + cells, revealing high expression in 5ALA + cells relative to Core and Invasive margin (Fig. 4O).