Although there was overlap with the response of fibroblasts and keratinocytes to UVR there was a greater overlap with transcripts that correlate highly with expression of the DNA double strand break (DSB) repair genes BRCA1 and BRCA2 and the DNA damage response genes ATM and CHEK2. The exact cause of this overlap in transcripts is unknown but given that there is a certain level of redundancy between DNA repair processes, it is feasible that double strand break (DSB) repair may be compensating for the NER deficiency in the melanoma cell lines. This evidence concerns the gene CHEK2 and melanoma.