BMP4 and glioblastoma: Finally, to investigate if the underperforming MSC donor (MSC1), despite showing anti‐glioma effects in vitro, can replicate the previously reported survival outcomes of the BMP4 engineering platform compared to MSC‐NP controls,21 animals were evaluated for recurrence‐free survival in the first application of a resection and recurrence model of human GBM using PBAE‐based MSCs engineering.