This may be caused by several factors: first, palmitic acid can reversibly bind to albumin to prolong the blood retention time and reduce the elimination of peptides [21]; second, 177Lu-palm-3PRGD2 is amphiphilic and may self-assemble to form tiny nanoparticles (possibly nanospheres or nanofibers) with larger molecular sizes, resulting in longer blood retention times and higher tumor uptake [33,39]. Here, ALB is linked to neoplasm.