Final answer:
A Sertoli cell tumour is a type of testicular cancer that develops from Sertoli cells, which are essential in sperm development and function to nurture and protect germ cells within the testis.
Step-by-step explanation:
Sertoli cell tumour is a form of testicular cancer that originates from the Sertoli cells, which are a type of supporting cell also known as sustentacular or sustentocyte. These cells play a critical role in the process of spermatogenesis, the development of sperm, by surrounding and nurturing the developing sperm cells within the seminiferous tubules of the testis. Sertoli cells secrete signaling molecules that promote sperm production and regulate the survival of germ cells. They are integral to the formation of the blood-testis barrier, which protects germ cells from bloodborne substances and prevents an autoimmune response by isolating the antigens on the surface of developing germ cells from the bloodstream.
They also create the blood-testis barrier, which prevents harmful substances from reaching the germ cells and protects against autoimmune responses.