To investigate the association between JAK2 gene rs2230724 polymorphism and the risk of colorectal cancer.

The polymorphisms of JAK2 rs2230724 gene in 110 colorectal cancer patients（case group）and 150 non-tumor patients（control group）were analyzed by polymerase chain react-restriction enzyme fragment length polymorphism（PCR-RFLP），and the association between the polymorphisms and the risk of colorectal cancer was evaluated. SPSS 26.0 software was used for analysis. Goodness-of-fit chi-square test was used to detect Hardy-Weinberg equilibrium. Student’s t test and Pearson χ² test were used to compare the general data，genotype and allele frequency distribution between the two groups. The association between JAK2 rs2230724 polymorphism and colorectal cancer risk was analyzed by Logistic linear regression（correction required），and the relative risk was estimated by odds ratio（OR）and 95% confidence interval（CI）. P<0.05 was considered statistically significant.

The frequency of A allele in the case group was significantly higher than that in the control group，and A allele mutation increased the risk of colorectal cancer by 50%（P=0.025，OR=1.50，95%CI=1.05-2.14）. Compared with the wild genotype（GG），the variant genotype（AG+AA）increased the risk of colorectal cancer by 79%（P=0.043，adjusted OR=1.79，95%CI=1.02-3.15）. Among them，mutation homozygous（AA）genotype carriers had 129% increased risk of colorectal cancer（P=0.034，OR=2.29，95%CI=1.06-4.93），and the difference was statistically significant. However，the difference was not statistically significant after adding adjustment factors（P=0.052，adjusted OR=2.29，95%CI=0.99-5.26）. Moreover，in stratified analyses，the polymorphism was associated with an increased risk of CRC in older age groups（age >56），non-smoking subjects，and urban residents（P<0.05）.

JAK2 rs2230724 polymorphism is associated with increased risk of colorectal cancer in Jiangsu Han population.