Among the top 5 differentially expressed genes (Fig. 5H), CCND1 plays a crucial role in cell proliferation and has been implicated in tumor invasion and metastasis (Fusté et al. 2016); the expression of CXCL14 is an independent marker of poor prognosis in breast cancer (Sjöberg et al. 2016); the high expression of KRT18 has been associated with deep tumor infiltration and correlates with tumor invasiveness and drug resistance, holding potential value in the diagnosis and prognostic assessment of breast cancer (Zhang et al. 2019). This evidence concerns the gene CCND1 and breast cancer.