We mapped the miRNA target sites identified by CLASH experiments (26) to their genomic location using Ensembl (37). SNPs and INDELs in the genomic locations of the target sites were then collected from the dbSNP table in the UCSC genome browser. More than 18 000 miRNA binding sites from CLASH data were searched for polymorphisms. We found 24 026 of polymorphisms located in these miRNA target sites, including 22 979 SNPs and 1047 INDELs (Table 1).