MTOR and chordoma: Of note, it was reported that PTEN-negative cells have enhanced sensitivity to mTOR inhibitors [34,35], indicating that Rapamycin treatment in PTEN mutated tumours may be even more effective as compared to sporadic chordomas with a preserved expression of PTEN providing a rationale for the treatment with mTOR inhibitors and making our cell line a unique and useful preclinical model.