The quantitative comparison of the ex vivo PCs formed upon incubation of AuNPs with serum samples obtained from BC patients revealed 75 deregulated subtype-specific unique proteins (8, 27, 2, 28 and 10 proteins specifically associated to the LA, LB-, LB+, HER2+ and TNBC subtypes, respectively). Here, ERBB2 is linked to breast cancer.