Some of the potential factors of resistance, such as poor internalization, defective intracellular trafficking of the HER2 antibody–drug conjugates, masking of the HER2 epitope, high rate of recycling, and the effect of upregulated drug efflux pumps, may be resolved by novel nanomedicines designed to interact with the tumor cells in a variety of ways with the goal of overcoming the limitations of the conjugates [68–69]. This evidence concerns the gene ERBB2 and neoplasm.