Table 1.

Statistics of rarely mutated chromosomal arms

	Deletions					Duplications
Chromosomal arm	4q	9q	13q	15q	18q	7p	7q	11q
TCGA: OD II + III	9.8%	4.5%	10.5%	9.0%	15.0%	6.0%	9.0%	4.5%
TCGA: OD III	13.8%	5.2%	10.3%	12.1%	20.7%	6.9%	10.3%	6.9%
POLA: OD III	16.2%	14.7%	5.9%	14.7%	8.8%	4.4%	7.3%	19.1%

Chromosomal arms affected by deletions (4q, 9q, 13q, 15q and 18q) and duplications (7p, 7q and 11q) in subsets of oligodendrogliomas in addition to the characteristic 1p/19q co-deletion. Percentages of affected oligodendrogliomas are shown for the TCGA cohort (TCGA: OD II + III comprised 133 oligodendrogliomas of WHO grades II and III, TCGA: OD III comprised 58 oligodendrogliomas of WHO grade III) and the POLA cohort [33] (POLA: OD III comprised 68 oligodendrogliomas of WHO grade III)