However, five genes (CDC20, MET, KIF23, ANXA1, and CASP1) that are found in the TNBC group were not highly expressed in the HR+ breast cancer subtypes but are commonly found in the ER−/PR+ and ER−/PR− groups such that they could be used as negative controls [26,28] (Figure 2b). This evidence concerns the gene KIF23 and breast carcinoma.