Overall, the present paper demonstrates that preventing deSUMOylation by adrenocortical-specific SENP2 ablation in mouse induces zF hypoplasia associated with increased premature apoptosis along the lineage conversion zG-zF process, ultimately resulting in a blockage of the physiological differentiation process, translating to isolated glucocorticoid deficiency. The gene discussed is SENP2; the disease is familial glucocorticoid deficiency.