C4orf51 and breast cancer: Moreover, among upregulated hub genes, we found many genes displayed good diagnostic efficacy for BRCA1/2-mutant breast cancer compared to wild-type breast cancer, including CCNE1, NPBWR1, A2ML1, TTK, C4orf51 (Chromosome 4 open reading frame 51) and EXO1 (Exonuclease 1), with AUC value >0.630 and P-value <0.05.