PALB2 and hypoparathyroidism-retardation-dysmorphism syndrome: Nones et al.17 took a similar approach using fresh frozen tumors and were able to show that all but one causally unexplained BCs with HRD were due to inactivation of BRCA1, BRCA2, or PALB2. Taken together with the results we present here, we can conclude that the tail of missing heritability due to HRD genes must be long and thin.