Analysis of KEAP1 promoter region methylation status in CRC cell lines. (A) Results of MSP in 10 CRC cell lines. (B) Results of BSP. Representative methylation analysis of CpG islands at the promoter region of the KEAP1 gene (upper). Methylation is indicated in red. Methylation status of each of the 12 CpG sites in 10 CRC cell lines (lower). Black circles represent methylated CpGs. White circles represent unmethylated CpGs.