Many of the consistently and abundantly over expressed transcripts in trisomic BG01V APCs and CCF-STTG1 astrocytoma cells encode proteins previously implicated in cancer in general or associated with astrocytomas specifically, including HSPA1A, HOXD10, GPNMB, GUCY1B3, GUCY1A3, HDAC9, APOE, CTSH, THRB, RAB38 and PIK3R1 [10-21]. This evidence concerns the gene PIK3R1 and cancer.