Using a surrogate panel of 5 immunohistochemical antibodies (ER, PR, HER2, CK5, and EGFR) the molecular subtypes can be approximated in formalin-fixed paraffin-embedded tissue sections and using these techniques a number of authors have found that HER2 enriched DCIS (~15–20% of DCIS cases) appears to be more frequent and basal-like DCIS (~4–8% of cases) are less frequent than their invasive counterparts [43–45]. This evidence concerns the gene KRT5 and ductal breast carcinoma in situ.