On the other hand, when they treated HPV-positive HNSCC cell lines with selective CB1 agonist ACAE, selective CB2 agonist Hu 308, and non-selective cannabinoid receptor agonist THC at doses similar to those experienced by marijuana users for recreational purposes, they observed an increase in cell proliferation compared to normal cell lines. This evidence concerns the gene CNR2 and head and neck squamous cell carcinoma.