CYP17A1 and endometriosis: To assess if there is expression of the key enzymes in the metabolisation of pregnenolone and DHEA (i.e., CYP11A1 and CYP17A1) or PS and DHEAS (i.e., SULT1E1, SULT2A1, and SULT2B1) (Figure 1, Figure S1) in endometriosis, we first consulted a publicly available single-cell RNA sequencing dataset by Fonseca et al. [33], containing two healthy control individuals and paired eutopic endometrium and endometriosis tissue (EL) from two endometriosis patients.