Secondly, GSTP1 functions as a caretaker gene [53, 58, 59] with its loss resulting in increased oxidative DNA damage and mutagenesis, thus, in BRCA2 deficient cancers already sensitive to oxidative stress [60], any loss of GSTP1 may have a more pronounced effect and be integral in tumour development. The gene discussed is GSTP1; the disease is neoplasm.