{{Rsnum
|rsid=521102
|Gene=CHEK1
|Chromosome=11
|position=125644678
|Orientation=minus
|GMAF=0.4325
|Assembly=GRCh38
|GenomeBuild=38.1
|dbSNPBuild=141
|geno1=(C;C)
|geno2=(C;T)
|geno3=(T;T)
|Gene_s=CHEK1
}}{{ population diversity
| geno1=(C;C)
| geno2=(C;T)
| geno3=(T;T)
| CEU | 26.5 | 46.9 | 26.5
| HCB | 32.4 | 50.0 | 17.6
| JPT | 38.1 | 43.4 | 18.6
| YRI | 55.5 | 39.7 | 4.8
| ASW | 48.2 | 42.9 | 8.9
| CHB | 32.4 | 50.0 | 17.6
| CHD | 31.5 | 51.9 | 16.7
| GIH | 18.8 | 58.4 | 22.8
| LWK | 63.6 | 30.9 | 5.5
| MEX | 13.8 | 46.6 | 39.7
| MKK | 57.1 | 37.2 | 5.8
| TSI | 21.6 | 55.9 | 22.5
| HapMapRevision=28
}}[[rs521102]], also known as IVS11 +35, G>A, is a SNP in the [[CHEK1]] gene.

In a study of 119 American patients with potentially resectable [[pancreatic cancer]], the [[rs521102]](T) allele was associated with poorer overall survival (ie response) to combined gerncitabine radiation therapy. Also, as 1 of 3 SNPs its risk allele is associated with poorer overall survival for [[pancreatic cancer]] patients being treated with combined gerncitabine radiation therapy; median overall survival times of 31.0, 16.2, and 10.5 months were calculated for [[pancreatic cancer]] patients carrying < or = 1, 2, and 3 risk alleles from [[rs664143]](C), [[rs2227928]](C), and [[rs521102]](T;T), respectively (P=0.004).
{{PMID|18381943|OA=1
}}

{{on chip | 23andMe v3}}
{{on chip | 23andMe v4}}
{{on chip | FTDNA2}}
{{on chip | FTDNA}}
{{on chip | HumanOmni1Quad}}
{{on chip | Illumina Human 1M}}