Description of read-through KLK4-KRSP1. (A) DNA: Genomic structure of KLK4 and KRSP1 on the DNA (−) strand. RNA: At least five isoforms are expressed from the genomic locus. A pink line represents the splice site in KLK4 exon 2 which leads to a frameshift and subsequent STOP codon in the RNA and the use of an alternative (alt) ATG START codon in putative KKv1 and KKv2 proteins. Green and brown lines indicate the splice sites in KLK4 exon 5 (5 m = exon 5 middle, 5 m2 = exon 5 middle with different splice site) utilized in KKv2 and KKv3, respectively. TaqMan assay positions and the positions targeted by siRNAs are indicated. (B) Expression levels of KLK4-KRSP1 isoform 1 (KKv1) in 46 frozen tumor/normal sample pairs using TaqMan assay. (C) KKv2 expression in tumor/normal tissue pairs was screend for 46 KKv1-positive samples.