The same animals showed smaller seminiferous tubules and less lumen development than the controls.[1] Similarly variable degrees of maturation arrest in different stages of spermatogenesis with reduced diameter of seminiferous tubules were noted when rats were fed with zinc deficient diets.[2] Zinc deficiency causes a reduction in the structural parameters of seminiferous tubules influences serum levels of testosterone (T) and prolactin (PRL) in rats.[3, 4]. The gene discussed is PRL; the disease is Zinc deficiency.