To determine if Pkd1 loss affected response to these drugs, we induced loss of Apc and Pkd1 with tamoxifen treatment of 12-week-old mice, and commencing at week 13, treated mice weekly with either vehicle, or with standard DNA-damaging cytotoxic chemotherapies for CRC, FOLFIRI and FOLFOX (Fig. 5C). Here, APC is linked to colorectal carcinoma.