ESR1 and breast cancer: PTK7 genetic alterations in invasive breast carcinoma were analyzed using cBioPortal for Cancer Genomics (http://www.cbioportal.org/) breast cancer datasets and the results revealed that PTK7 genetic amplification exists in 1.6% cases (n = 30) of invasive breast carcinoma patients (n = 1,904), most of which are ER(-), PR(-) and HER2(-) (TNBC, n = 22) (Supplementary Figure S1B).