Importantly, as shown in Figure 5D, confocal immunofluorescence analysis of a human seminoma specimen (S4 derived from patient P4) showed that PTTG1 and ZEB1 significantly colocalized in isolated cells present on the fringes of the tumors where PTTG1 showed nuclear staining, as was previously reported [16]. Here, PTTG1 is linked to seminoma.