Allelic discrimination plots of the six tested single-nucleotide polymorphisms (SNPs) in the mucin 4 ( MUC4 ) gene. The DNA samples from patients and controls were genotyped by using the TaqMan SNP Genotyping Assay System. The major (also the wild-type) alleles were detected by 6-carboxyfluorescein (FAM)-labeled probes (blue), and the minor alleles were detected by 2'-chloro-7'-phenyl-1,4-dichloro-6-carboxyfluorescein (VIC)-labeled probes. The genotyping results of the six SNPs in the MUC4 gene are presented as allelic discrimination plots. Of note, the intensity of FAM signals tended to be similar among samples in our assays, thus the dots for a wild-type genotype overlapped each other. "X" indicates the participant who failed to be genotyped.