BRCA1 and neoplasm: DSBR deficient strains carrying a deletion in brc-1, the C. elegans ortholog of the BRCA1 tumour suppressor, exhibited a uniform base substitution spectrum and increased rate of small deletions and tandem duplications (Fig. 1c), features also observed in BRCA1 defective cancer genomes (c = 0.69 relative to SBS3)18.