Using transferrin-facilitated cellular targeting as a model system (which has been widely applied in cancer-related research20–22), we demonstrate that cadmium chalcogenide nanocrystals with specific facets (i.e., (100) facet of cadmoselite and (002) facet of greenockite) preferentially bind with transferrin via inner-sphere coordination in a complex protein matrix, which significantly enhances receptor-mediated delivery of the nanocrystals into cancer cells. Here, TF is linked to cancer.