A breast CoC was effective in capturing the efficacy of transferrin targeted‐AuNPs (Tf‐AuNPs), where Tf improved accumulation at the tumor site in the CoC chip by 15 folds.[69] In animal studies, the Tf‐targeted AuNPs exhibited a deeper penetration compared to the pegylated, non‐targeted AuNPs, which agrees with the CoC results and indicates the efficacy of Tf targeting and the accuracy of CoC platforms. Here, TF is linked to neoplasm.