For example, among 60 upregulated genes unique to those aged ≤40 years, 16 gene products were found to be present in EVs secreted by breast cancer cell lines, of which 7 proteins (i.e., PGBD5, NPY1R, PLA2G2D, SLC38A5, F5, COL5A2, and COL5A1) were also common to other cancer cell lines, 4 proteins (i.e., LLGL2, TLL2, APT6V0D2, and HIST1H2AE) were in urine, saliva, or breast milk, and 5 proteins (i.e., NME1, COL1A2, HSPB1, DHRS2, and APOC2) were in breast cancer cell lines and human body fluids such as urine, saliva, breast milk, and plasma (Figure 8). This evidence concerns the gene COL5A1 and breast cancer.