LINE-1 methylation in stage IIIC CM patients. LINE-1 methylation at 3 CpG sites (CpG1, CpG2, CpG3) was evaluated by bisulfite pyrosequencing analysis in short-term cultures of CM cells generated from neoplastic lesions of 42 stage IIIC melanoma patients. All cells were analyzed at 6th in vitro passage. Separate box plots have been generated for each of the CpG sites under analysis. Black horizontal bars represent the median values of methylation for each group.