There are barriers to estimating risk for BARD1 variants: i) the rarity of carriers of potentially pathogenic BARD1 variants; ii) the posited low–moderate risk of cancer associated with BARD1 variants; and iii) the heterogeneity within and between populations, cancer cases of the same primary tissue site and cancer subtypes (based on histopathology or biomarkers). The gene discussed is BARD1; the disease is cancer.