Analysis of BC patient sera revealed overexpression of six proteins—albumin, gelsolin, fibrinogen γ chain, immunoglobulin α-1 chain C region, immunoglobulin α-2 chain C region, and haptoglobin—which were proposed as BC-associated biomarkers, offering a rapid, low-cost marker‐discovery strategy (Figure 8) (Araújo et al., 2018). Here, HP is linked to breast cancer.