PTEN and glioblastoma: We tested the cinobufagin antiproliferation effect on other GBM cells LN229-EGFR and SF763-EGFR, which overexpress EGFR and have normal PTEN, and observed that cinobufagin had less effect on LN229-EGFR and SF763-EGFR than that on PTEN-deficient U87MG-EGFR.