The expression of key markers associated with proliferation (MKI67, PCNA, CCNB1, MYBL2, BUB1, CCND1), apoptosis (BCL2, CASP7, CASP8, CASP9, CASP3, BAX, APAF1), differentiation (CDH1, CD24, EPCAM, ESR1, NGFR, RUNX1), and breast cancer stemness (CD44, ITGA6, DNER, ALDH1A3, ABCG2, PROCR) was assessed. This evidence concerns the gene CASP9 and breast cancer.