The number of expressed CT genes was significantly higher in seminomas (P = 3.48 × 10<sup>-13</sup> ) which were characterized by frequent mutations in driver genes (KIT, KRAS and NRAS).
Using the polymerase chain reaction (PCR) and allele specific oligonucleotide hybridization (ASO), mutations were found in five SE (three in NRAS and two in KRAS, all codon 12), and in one NS (KRAS, codon 12).