BIM promoter methylation analysis. (A) MSP analysis of the BIM promoter in the PC9 cell lines. PC9 and its two derivative, gefitinib resistant cell lines all presented with hypo-methylated BIM. (B) Pyrosequencing analysis of all studied cell lines. Blue regions mark the analyzed positions. (C) Comparison of the BIM methylation index by pyrosequencing and nested q-MSP in all studied cell lines. BIM, bcl-2-like protein 11; MSP, methylation specific polymerase chain reaction; q-, quantitative; M, methylated; U, unmethylated.