SMG1 and head and neck cancer: We recently found that knockdown of an important player in DNA damage response, SMG-1, in cancer cells led to their increased sensitivity to roscovitine [58]; furthermore, expression of SMG-1 was diminished in HPV-positive HNSCCs due to SMG-1 promoter hypermethylation [59] that may contribute to the sensitivity of HPV+ head and neck cancer cells to roscovitine.