Human Sertoli Cells (SerC) are essential for testicular development, spermatogenesis, and formation of the blood-testis barrier. SerC limit the passage of substances such as hormones and nutrients to the adluminal compartment of the seminiferous tubules. In addition to forming the blood-testis barrier, SerC also provide the main structural support for the seminiferous tubules. They protect the germ cells from the immune system. Aberrant SerC proliferation can contribute to the development of male reproductive disorders; such as testicular germ-cell cancer, cryptorchidism, hypospadias, and low sperm count. SerC proliferation is in part dependant by follicle-stimulating hormone (FSH) and thyroid hormone (TH), where FSH drives proliferation and TH promotes a more quiescent state. Cultured Human SerC are a useful in vitro model to better understand testicular dysgenesis syndrome and to develop treatments for male reproductive disorders.