They hypothesized that PARP-1 overexpression, in some cases, may result from defective PARP-1 cleavage, resulting in reduced tumour apoptosis (see also the previous report of Tang et al.).72,75 Similar results were obtained in a study of ovarian cancer.76 We have demonstrated, for the first time, that metastasizing OSCCs are characterized by constant high expression of PARP-1 (almost entirely full-length) coupled to hyperexpression of CAF-1/p60 and nestin, regardless of the grade and size of tumours at diagnosis. This evidence concerns the gene NES and ovarian cancer.