Somatic coding indels in NF1 (3/10 gliosarcoma samples), PTEN (2/10), RB1 (2/10) and PIK3R1 (2/10) genes with a minimal penetration of 15% (within a given sample) were found in 5/10 samples (Table 2 and Figure 1). Here, PIK3R1 is linked to gliosarcoma.