To assess the impact of complete loss of Prkar1a on adreno-cortical function and initiation of PPNAD, we crossed the Akr1b7:Cre line [13] with mice carrying the conditional null allele Prkar1aloxP[6] to produce adrenal cortex-specific KO mice of the Akr1b7:Cre;Prkar1aloxP/loxP genotype (Figure 1A). This evidence concerns the gene PRKAR1A and primary pigmented nodular adrenocortical disease.