Upon comparison of this pathway in malignant and benign tumours, it was seen that, in malignant tissues ATM/ATR kinases having role in controlling BRCA1 phosphorylation in vivo are involved in regulation of G2/M DNA damage checkpoint, while in benign tissues, activation of alternative AURKA–PLK1 pathway may play that role (Fig 10). This evidence concerns the gene PLK1 and neoplasm.