Tracing the network connecting BRCA and Fanconi anaemia proteins

Recent evidence connects the proteins that are encoded by the BRCA1 and BRCA2 breast cancer susceptibility genes, and other tumour suppressors - such as the Fanconi anaemia gene products - to cell-cycle checkpoint control and DNA repair by homologous recombination. Do these connections represent a linear biological pathway or do they, instead, reflect a network of processes that prevent aberrations in chromosome structure during the S and G2 phases of the cell cycle? This distinction has important implications for current models to explain the pathogenesis of the cancer susceptibility syndromes that are associated with BRCA or Fanconi anaemia gene mutations.