High levels of nuclear SOX11 were detected by IHC in ER– DCIS lesions as compared with ER+ DCIS lesions (P = 0.0002, Fisher's exact test) in a small cohort of pure DCIS cases (13/22 ER–, six of 17 HER2+, one of 22 ER+, and DCIS and invasive components of four of six mixed cases) (Figure 6C, D; supplementary material, Figure S10). Here, SOX11 is linked to ductal breast carcinoma in situ.