The results of in vivo and in vitro experiments showed that asparagus extracellular vesicles inhibited the proliferation of cancer cells by reducing the expression levels of Ki67 and PCNA in liver cancer cells, and increase the protein levels of AIF, Bax and Bak to trigger the activation of caspase-9, leading to cleavage of key cellular proteins including the DNA repair enzyme PARP and ultimately cancer cell death (Zhang et al., 2021). Here, PCNA is linked to cancer.