ESR1 and neoplasm: More than 80 % of the tumor cells were also reactive to estrogen receptors (ER) and progesterone receptors (PR), synaptophysin and chromogranin A. About 50 % of tumor cells were detected to be positive to androgen receptors (AR), but both two types of tumor cell did not express CK20, mammaglobin and myoepithelial cells markers, such as CK5/6, S-100 protein and p63 (Fig. 2).