To explore the gene-specific copy-number alterations (CNA) of PLK2 (chromosome 5q11.2), we analyzed the TCGA Pan-Cancer and Tumorscape datasets using the TCGA Copy Number Portal from the Broad Institute and confirmed that PLK2 is significantly deleted in several types of cancer, including breast cancer (Fig. 1A; Supplementary Fig. S1A). This evidence concerns the gene PLK2 and breast cancer.