FOXK2 and invasive ductal breast carcinoma: To ascertain further the physiological and clinical importance of the regulation of FOXO3a by FOXK2 in breast cancer, FOXO3a and FOXK2 expression was assessed by immunohistochemistry in 86 invasive ductal carcinoma patient samples, of which 46 received anthracyclin and taxane chemotherapy treatment (Figure 9a; Supplementary Figure S10).