PCNA and cervical cancer: In oncologic aspect the extract of Gleditsia sinensis thorn could prevent colon cancer in vitro and vivo through the induction of G2/M cell cycle arrest and extracellular signal-regulated kinase 1/2 (ERK1/2) activation [10], and cervical cancer in vivo through down-regulation of proliferating cell nuclear antigen (PCNA) and mutant p53 [11].