RASSF1 and astrocytoma (excluding glioblastoma): Two astrocytomas (samples 7 and 30) and the cell line T98G were sequenced in the promoter of the RASSF1A gene: sample 30 and the T98G cell line were strongly methylated while sample 7 presented a lower degree of methylation (3 to 16 of the 32 CpGs analyzed were methylated in the different clones).