Germline development in vivo is dependent on the environment formed by somatic cells and the differentiation cues they provide; hence. the impact of local factors is highly relevant to the production of sperm. Knowledge of how somatic and germline cells interact is central to achieving biomedical goals relating to restoring. preserving or restricting fertility in humans. https://www.roneverhart.com/SAAB-9-3-I-98-02-Frontlykt-Hoyre/