OTX1 and lung cancer: Pyrosequencing also suggested that β-values from the 450K array seemed to be slightly inflated than true values; for example, a cg27364741 locus at the OTX1 gene that is known to be significantly methylated in lung cancer showed higher methylation in 450K array than in pyrosequencing, suggesting background signal of the 450K array (Figs. 1b, c).