PGR and medullary thyroid gland carcinoma: For instance, GATA3 is not only detected in metaplastic and lobular breast cancer of TNBC, but also is highly expressed in other subtypes.18 Moreover, it has been reported that medullary carcinoma had the lowest tissue levels of estrogen and progesterone receptors while mucinous carcinoma had the highest percentages of positive estrogen and progesterone receptor levels.19 In our study, most patients with TNBC were invasive ductal carcinoma not otherwise specified.