 This study examined the size-dependent endocytosis of gold nanoparticles, AUNPs, in various cancer cells. It found that smaller AUNPs had higher uptake rates than larger ones, as they could enter cells more easily via endocytosis. Larger AUNPs, however, were better suited for drug delivery because they were less likely to be trapped on the cell membrane. This article was authored by Li Kewei, Wang Shemhan, Chu Arthur, and others.