“…Notably, if the HPV-related OPSCC rate is extremely variable, in the series where p16 IHC and nucleic acid detection are both performed, the false positive rate (FPR) of p16 IHC among HPV-negative cases is between 5 and 20% [ 11 , 18 , 35 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], and is pretty constant for a given assay even in different populations (such as Dutch and Sardinians) (ISH, DNA detection without amplification, PCR) (some examples are shown in Table 2 ). When the current standard for the diagnosis of HPV-driven carcinogenesis is used (mRNA detection or sequential p16IHC and HPV-DNA PCR), the rate of HPV-negative OPSCC expressing p16 is notably always about 5.5% [ 11 , 44 , 45 , 46 ].…”