CHEK2 and thyroid cancer: The most common gene with PVs identified in the eoRC patients was the DDRR gene CHEK2 (19/844, 2.25%, Fig. 2A, Table S3 and S4), consistent with a recent report by Carlo et al.16 Of patients with CHEK2 PVs, 47.3% (n = 9/19) had a common, highly damaging variant (c.1100delC, p.Thr367Metfs) that is known to be associated with an increased risk for breast, prostate, colorectal and thyroid cancers (Table S4)34–37.