Summarizing this meeting has been a daunting but gratifying assignment. Although I performed this role in the past meetings, I had a new sense of excitement as I unfolded the presentations of the last two and one-half days. Whereas the formal presentations were outstanding, some of the discussions were even better.
Throughout the meeting, the astrocyte -fetal and adult, normal and neoplastic -has been the focus of attention. This is understandable, because by their sheer numbers and the opportunity that they provide for studying tumor progression and diversity, astrocytomas completely dominate primary tumors of the CNS.
In this summary, omission of a presentation does not reflect its lack of importance but rather my inability to weave it into the overall fabric of the meeting's major themes.
Appropriately, the meeting began with a search for astrocyte-specific genes and gene products. Already familiar is the enormous value of GFAP. For two decades, GFAP has been used to answer the question, 'what is an astrocyte?' Lipocortin 2 -LC 2-is another such genetic marker. It is expressed in early fetal development but, with maturation, the gene is no longer expressed in adult astrocytes. Neither is it expressed in differentiated astrocytomas, but expression has been found in a small number of anaplastic astrocytomas and in every glioblastoma examined to date. The gene is located on the long arm of chromosome 10 and may contribute to the enhanced aggressiveness of glioblastomas, which are known to have alterations of this chromosome.