Steroidogenic factor-1 (SF1), encoded by the NR5A1 gene (orphan nuclear receptor subfamily 5 group A member 1) located on the long arm of chromosome 9, is a key factor involved in gonadal embryogenesis, sex determination, and reproductive endocrine regulation and plays a pivotal role, especially in the context of 46,XY DSD [12,13,14,15,16]. The gene discussed is NR5A1; the disease is disorder of sexual differentiation.