MAGEA1 and astrocytoma (excluding glioblastoma): According to reports, MAGEA1 expression could be detected in 0-38% of GBM cases evaluated in three studies, whereas SSX2 mRNA positivity was present in 0-29% of tumors examined by three independent investigations and MAGEA3 (0-22%) and SSX4 (0-27%) gene products were detectable in different proportions of grade IV astrocytomas.