Among the shared upregulated genes in normal breast tissues and breast tumors, the expression of five genes unique to young women aged ≤40 years with BC (i.e., COL1A2, COL5A2, COL5A1, NPY1R, and KIAA1644) significantly affected the OS and RFS of patients with several tumor subtypes (Figure 4a). This evidence concerns the gene NPY1R and breast neoplasm.