Positions of DHFR* integration sites and fragile sites. The DHFR* integration sites were mapped onto the genome using BLAT  and are shown as a red bar on the chromosome ideogram from the UCSC genome browser . Common fragile sites are shown under the chromosome and are mapped according to positions reported in NCBI Entrez and the literature [65-77]. Rare folate sensitive fragile sites are shown above the chromosome. Note that the 1M-45DHFR* integration site mapped just proximal to FRA11B, another folate sensitive fragile site; however, no copy number transitions or amplicon boundaries mapped to this region. Since FRA11B is a RFS, it may not be expressed in HCT116.