Impaired KLF4 or PARP1 has been previously linked to breast cancer formation (Foster et al, 2000; Pandya et al, 2004; Rowland et al, 2005; Fletcher et al, 2011; Rojo et al, 2012; Li et al, 2013; Green et al, 2015; Orr et al, 2015). This evidence concerns the gene PARP1 and breast cancer.