As the SNP T allele is associated with reduced NO levels it was surprising that, in the present study, patients carrying the GG phenotype exhibited a three-fold increased risk of VTE compared to T allele carriers (OR = 3.0; χ2 test, p = 0.023) However, data specifically addressing the association between NOS3 rs1799983 and cancer-associated VTE are limited, and findings on its involvement in cancer development are inconsistent, thereby questioning the utility of this SNP as a biomarker [23–26]. This evidence concerns the gene NOS3 and cancer.