Table 1.

Frequency of CpG hypermethylation in lung tumours

Gene	Methylation levels Maximum/Minimum/Average	Methylation level cut-offˆ	Hypermethylated tumor samples* (%)
CHRNα3	64.83% / 0% / 21.14%	22.67%	52/142 (36.6%)
CHRNβ4	51.14% / 0% / 13.36%	15.03%	30/124 (24.2%)
CHRNα5	7.51% / 0% / 1.57%	5.72%	7/103 (6.8%)

^ˆThe 90% percentile value for surrounding non-tumour lung tissue samples.

^*Samples with methylation levels above the quantile representing the upper 90% of methylation in surrounding non-tumour lung tissue samples.