Specifically, our xenograft mouse models showed that PARP1 expression was, with levels of 37.2 ± 3.2% and 28.7 ± 1.7% (for FaDu and Cal 27, respectively), 26-fold and 21-fold higher in tumor tissue than tongue tissue (1.4 ± 0.4%, Fig 1). This evidence concerns the gene PARP1 and neoplasm.