The mRNA expression levels of CCND3, DUSP10 and RAP1GAP were higher in TIL-rich DCIS compared to TIL-poor DCIS, with a median Log2 value of 5.60 vs. 3.50 for CCND3, 7.17 vs. 4.44 for DUSP10 and 6.20 vs. 3.58 for RAP1GAP, respectively. This evidence concerns the gene CCND3 and ductal breast carcinoma in situ.