For this objective, which focuses on identifying factors associated with success of EES, bivariate regression analysis identified the following candidate variables: age (p=0.01), number of preoperative insufficiencies (p=0.082), lower pre-operative prolactin levels (p=0.1616), not first time surgery (i.e. rank of surgery > 1)(p=0.001), number of new immediate postoperative insufficiencies (p=0.178), immediate postoperative AVP deficiency or SIADH (p=0.027), gonadotroph adenoma subtype (p=0.006), somatotroph adenoma subtype (p=0.012) and mammosomatoroph adenoma subtype (p=0.078). The gene discussed is PRL; the disease is functioning gonadotropic adenoma.