UCSC screenshot of the chromosome 19 region containing IL28A, IL28B and IL29. Coordinates are from hg19. IL28A and IL28B lie within segmental duplications. The locations of these duplications are reflected in areas of poor mapability, as indicated by low scores on the CRG Align 75 subtrack. The score for this subtrack is the reciprocal of the number of matches found in the genome for 75 mers with no more than 2 mismatches. The track below this subtrack shows the location of the 19 SNPs that were individually genotyped using Sequenom. The four SNPs that best tagged the IL28B region haplotypes are indicated in blue. Screenshot taken from UCSC draft human genome .