CDK1 and pachyonychia congenita: In human samples of PC, Ito et al. showed that cell division cycle (CDC)2 expression was significantly higher in pancreatic adenocarcinoma than in intraductal or cystic adenocarcinoma [31/50 (54.8%) versus 3/13 (23.1%), p = 0.0418], and the overexpression of CDC2 was also demonstrated to be closely associated with lymph node metastasis and a high Ki-67 labeling index in these patients with PC [49].