FEN1 cytoplasmic median H-score was 10 (range 0–80), 50 (range 0–120), 70 (range 0–120) and 70 (range 0–100) in TDLU, pure DCIS cohort, DCIS component of the mixed cohort and IBC component, respectively (Fig. 2a–d). The gene discussed is FEN1; the disease is ductal breast carcinoma in situ.