What are germ cell and sex cord stromal cells? Germ cells and sex cord stromal cells form when a fetus (baby) is developing. A fetus is made from a sperm cell and an egg cell. Germ cell tumors (GCTs) ...
Two weeks after a human egg is fertilized, primordial germ cells (PGCs), which develop into sperm and eggs, are formed. In six to 10 weeks after fertilization, PGCs differentiate into pro ...