*3.3. Differences in Prevalence of HPV 16 Sub-Lineages between Anal Cancer and Control Cohort*

No major differences in the proportion of A1 and A2 sub-lineages were observed between the case vs. control cohorts, being 76.4% vs. 76.0% and 16.2% vs. 17.0%, respectively. Whereas the case cohort revealed the presence of the A4 sub-lineage in 4.2% of anal cancers, this sub-lineage was not present in the control cohort. Conversely, the C lineage was present in 1.5% of control specimens and was not detected in cancer cases. Finally, there was a slight increase in the D1 sub-lineage observed in the control vs. case cohort (3.0% vs. 0.8%).
