AFP and seminoma: Non-seminoma patients with CXCL12 expression in their primary tumor had significantly higher pre-orchiectomy AFP values (118.7 μg/l vs. 5.3 μg/l, p < 0.001) and b-HCG values (152.0 U/l vs. 8.2 U/l, p < 0.001) compared to CXCL12 negative patients (Fig. 2).