Figure 1.

Development of GCs and pathogenesis of TGCTs. Upper panel: Development of the human embryo from the zygote (0 day post fertilization [dpf]) until Week 6 post fertilization when the PGC reach the gonads. Lower panel: DNA methylation events during PGC migration and arrival at the genital ridge and where different types pf TGCTs are thought to originate from. The table summarizes molecular and epigenetic findings from this review. Data from Refs. [1,48,49,52,58,74]. PGC, primordial germ cell; ICM, inner cell mass; SE, seminoma; EC, embryonal carcinoma; CC, choriocarcinoma; TE, teratoma; YST, yolk sac tumor; NS, non-seminoma; GCNIS, germ cell neoplasia in situ; GC, germ cell; TGCTs, testicular germ cell tumors.