CTSS and neoplasm: In that respect, novel technologies enabling targeting of cells of the tumor microenvironment would be very potent in terms of the targeted delivery of cysteine cathepsin inhibitors to the cells of tumors primarily overexpressing cathepsins (e.g., macrophages) and would improve pharmacokinetic properties of small synthetic drugs by encapsulation in nano-carriers (Mikhaylov and Vasiljeva, 2011).