Combinatory exposure led to an increased mRNA expression of CYP11B1 (11.8-fold at 10 μM) and CYP11B2 (44.1-fold at 10 μM) as well as other steroidogenic enzymes (e.g., CYP21A2, HSD3B2) and key adrenocortical receptors (e.g., MC2R, AGTR1) when compared to untreated controls.<h4>Discussion</h4>This in vitro study provides novel evidence on phthalate- and substitute-induced endocrine disruption of adrenal steroidogenesis, favouring mineralo- and glucocorticoid secretion, potentially linking these substances to secondary hypertension. The gene discussed is CYP21A2; the disease is secondary hypertension.