Next, the expression of Star-PAP in human breast cancer tissues was examined by analyzing the public data sets.14, 15, 16 Although highly expressed in normal mammary tissues, Star-PAP was downregulated in ductal carcinoma in situ (Figure 1e), invasive ductal carcinoma (Figure 1f) and even the stroma of invasive ductal carcinoma (Figure 1g). This evidence concerns the gene STAR and ductal breast carcinoma in situ.