CTSB and cancer: To enable the CtsB-targeted delivery of diagnostics or therapeutics to the cancer site, NS-629 was incorporated through a lipid linker into the preformed sterically stabilized polyethylene glycol (PEG)-coated nanosized stealth liposomes, thereby forming a lipidated nanocarrier (LNC) capable of specific CtsB targeting (LNC-NS-629; Figure 1 a).