ALDH1A1 and ductal breast carcinoma in situ: Interestingly, ALDH1 was expressed in tumor cells in 41.3 % (19/46, one case not available) of DCIS cases, 45.0 % (27/60, two cases not available) of invasive cancer with EIC cases, and 93.1 % (54/58) of invasive cancer without EIC cases.