FSH acts on the Sertoli cells and stimulates the secretion of some factors which help in the process of 

FSH acts on the Sertoli (sustentacular) cells and stimulates secretion of some factors (e.g., androgen-binding protein) which help in the process of spermiogenesis. Androgen binding protein binds to testosterone, keeping its concentration high. Testosterone stimulates the final steps of spermatogenesis (spermiogenesis) in the seminiferous tubules. Spermiogenesis is the final stage of spermatogenesis, which involves the development of haploid spermatids into sperm.