FADS2 and Cowden disease: Interaction effect was tested but interaction effect size was not reported.The associations between the dietary PUFA ratio and risk of pediatric CD were dependent on CYP4F3 (rs1290617 and rs1290620) and FADS2 (rs11230815, rs17831757 and rs174627) genotypes.Interaction between rs11230815 in FADS2 and dietary ω3 intake was observed regarding the risk of pediatric CD (P interaction =.042).