 In addition, low expression of Ku80 was found in 15% of adenocarcinoma type and 32% of squamous cell type non-small cell lung cancers, and this was correlated with hypermethylation of the "XRCC5" promoter.Ku80 appears to be one of 26 different DNA repair proteins that are epigenetically repressed in various cancers (see Cancer epigenetics).Ku80 has been shown to interact with