ACTB and astrocytoma (excluding glioblastoma): Sema3C mRNA values determined in 74 gliomas (9 grade I astrocytomas, 28 grade II astrocytomas, 13 grade III astrocytomas, and 24 grade IV astrocytomas) were normalized to mRNA levels of the β-actin-encoding gene ACTB, which has been used as an internal control.