Searching for amplifications in low grade and high grade gliomas we observed an interesting correlation between the recurrence and progression of astrocytic low grade gliomas and the amplification of the STK15 gene located in the chromosomal region 20q13. Chromosome copy gains in this region have been reported previously in astrocytic gliomas and glioma cell lines and in many cancer types including breast, colorectal and ovarian cancers. The putative serine/threonine kinase STK15 has been reported to be amplified and overexpressed in breast cancer cell lines and colorectal cancer. Another candidate gene located in this region is PTPN1, a protein tyrosine phosphatase non-receptor type 1 that might play a role in cell cycle control. We used comparative PCR for quantitative DNA analysis to search for STK15 and PTPN1 amplification in gliomas previously characterized by CGH. Five out of 16 tumors (31%) of different WHO grade (1x grade II, 1x grade III, 3x grade IV) showed DNA amplification of STK15 whereas we did not detect amplification of PTPN1. We hypothesize that amplification of the STK15 gene may be a non-random genetic alteration in human gliomas playing a role in the genetic pathways of tumorigenesis.