ESR1 and ductal breast carcinoma in situ: Subjects with DCIS without microinvasion had a PLAC1 level of 57±32 ng/ml whereas, patients with HER2+, TNBC and ER+/PR+/HER2- disease had PLAC1 levels of 61±36, 63±27 and 117±245 ng/ml, respectively (Fig 1, Table 2).