The tumor specimens were separated into three distinct categories based on clinical results from two HPV assays (Fig. 2A): single positive 1 (SP1, positive for p16 IHC; n = 3), double positive (DP, positive for both p16 IHC and HPV ISH; n = 3), and DN (double negative, n = 4). This evidence concerns the gene CDKN2A and neoplasm.