PKD1 and invasive ductal breast carcinoma: Moreover, the immunohistochemical (DAB staining) analysis of progression tissue microarrays (TMAs) including normal breast tissue, ductal carcinoma in situ (DCIS), 3 groups of invasive ductal carcinomas (ER positive; HER2 positive; or TN) indicated that levels of total PKD1 are significantly decreased in invasive ductal carcinoma (Figure 4B), correlating with the data obtained for pS448-PIP5K1C in (Figure 2D).