ZIC2 and breast cancer: Furthermore, reverse transcription quantitative polymerase chain reaction (RT-qPCR), Western Blot, immunohistochemistry (IHC) and functional experiments (such as Cell Counting Kit-8 (CCK-8) assay, cellular migration assay and cell cycle assay) were all adopted to validate the expression level and significant clinical value of ZIC2 (one of the risk genes in the prognostic model) in cell lines and tissues of breast cancer.