MDK and endometriosis: Six analytes were increased in patients with endometriosis: ALDH1A (p = 0.002), CA9 (p = 0.005), CD44 (p < 0.001), hepsin (p = 0.008), midkine (p < 0.001), and TGM2 (p < 0.001), whereas concentration of a single marker – kallikrein-6, was found to be decreased (p = 0.006) (S2, S3).