BRCA2 and cancer: This is further corroborated by Rebbeck, Friebel [32] who reported LOH at only a single locus in four of 14 cancers reported in BRCA1/BRCA2 MINAS cases, which suggests that tumours develop from a second hit at a single PV and that the MINAS effect in BRCA1/BRCA2 MINAS is similarly, more likely to be additive.