CDKN2A and gliosarcoma: CDNK2A loss is common in 35–60% of GBMs and independently associated with worse overall and progression-free survival in both molecularly and histologically defined IDH-wildtype GBM31,35–37 In a microarray study of gliosarcomas, homozygous loss of CDKN2A was previously detected in 14 of 18 gliosarcoma specimens studied38.