AR and complete androgen insensitivity syndrome: This sex difference in digits has been linked to the prenatal hormonal environment through androgen receptors located in fetal cartilaginous tissue[14], and this tentative theory is supported by the following findings; lower 2D/4D in girls with CAH[15], higher 2D/4D in individuals with CAIS[16], and a relationship between 2D/4D and polymorphisms in androgen receptors[17].