PGR and ductal breast carcinoma in situ: The MIND system has also been used to analyze the effects of various genes on transition of pure DCIS to invasive tumors in vivo [100, 101]; however, it has only been used in a limited manner up until now to examine the role of steroid hormones on transition of DCIS to invasive cancer due to the previous lack of an ER+/PR+ human DCIS cell line (see below).