In a series of 46 glioblastomas, 16 anaplastic astrocytomas and eight astrocytomas, all tumours retaining one or both alleles of CDKN2A (48 tumours) and CDKN2B (49 tumours) were subjected to sequence analysis (entire coding region and splice acceptor and donor sites). Here, CDKN2A is linked to astrocytoma (excluding glioblastoma).