Analysis of the top 10 putative off-targets for AAVS1 ZFNs in targeted clones to rule out NHEJ mutations at those sites. Ten SELEX-predicted genomic off-targets were PCR-amplified and products sequenced for iXC1-APC-gp91 c3 (top chromatograph), iXC9-APC-gp91 c9 (middle chromatograph), and iXC9-APC-gp91 c21 (bottom chromatograph) for each of the 10 sites as indicated. Because the PCR products are from a homogenous population in each clone, mutations in the off-target sequence will show as single/double peaks/nucleotides that are different from reference sequence. None of these 3 clones showed any mutations in the off-target sequences.