WFDC2 and neoplasm: Two groups of low-risk patients are thus clearly defined: with CA125 levels < 35 IU/ml and HE4 levels < 142 pmol/l, and with CA125 levels < 35 IU/ml and HE4 levels > 142 pmol/l and a simultaneous absence of ultrasound evidence of myometrial invasion or tumour invasion of < 1⁄2 of the myometrium.