The CHEK2 nonsense c.1232G>A mutation on exon 11 resulted in a premature protein termination at codon 411 (p.Trp411Ter) predicted to disrupt protein function and occurred in the BR501 proband (BRCAPro 94%), affected with an early onset breast cancer at age 25 (Fig. 1). Here, CHEK2 is linked to breast cancer.