NF2 and neoplasm: The inference of the fraction of immune cells and consequently the tumour cell purity within tumour samples showed that the meningiomas in NF2 patients had significantly lower tumour purity (74.4% ± 7.3 in NF2 patients, 80.9% ± 5.2 in sporadic NF2-altered meningiomas, p = 0.02) and higher immune score (ESTIMATE score; p = 0.009, xCell immune score; p = 0.01, CIBERSORT absolute score; p = 0.01) when compared with sporadic NF2-altered meningiomas (Fig. 3A-D, Additional file 1: S5).