Figure 1

Differential genes are significantly repressed in association with methylation (SRAMs) in NSCLC cell lines. A) Example of the relationship between gene expression and methylation status for a single probe interrogating a single CpG site within the promoter region of CDKN2A. B) Frequency histogram of the Spearman rho values for all probes that correspond to either CpG or non-CpG island sites. Red curves are theoretical Gaussian representation of the distribution of rho given the number of probes for each gene set and the actual mean and standard deviation values; blue curves represent the empirical distribution from the data; dashed burgundy lines represent normal distribution curves for comparison; and the arrow identifies the point where the two curves cross and an excess of probes are seen with a rho ≤ -0.5. C) Relationship of rho to the distance from the transcriptional start site (TSS) for CpG and non-CpGi probes. Most of the probes (~80%) that are candidate SRAMs cluster within 500 bp of the TSS.