CASP3 and glioblastoma: In addition, PBCT induces a significant increase of cleaved caspase 3 IS, ES and IRS, where the last parameter was found to be increased 5-fold in PBCT treated mice as compared to alone proton irradiated mice, suggesting the PBCT ability to promote more apoptosis than PT, in line with previous studies on in vitro GBM model studies, where the combined treatment was able to significantly increase cell damages18–20.