In our previous study, we showed that 73/486 (15.6%) patients with PTC and 28/460 (6.0%) healthy controls had one of four mutations in CHEK2. Further, truncating CHEK2 mutations (1100delC, IVS2+1G > A, and del5395) were associated with higher risk of thyroid cancer (odds ratio [OR] = 5.7; p = 0.006) than were missense mutations (c.470T > A, I157T, and rs17879961) (OR = 2.8; p = 0.0001) [17]. This evidence concerns the gene CHEK2 and thyroid cancer.