CALCA and Patent ductus arteriosus: Because both KRAS mutation and ATDC overexpression occur in most human PDAs and oncogenic KRAS is needed for PDA development, we crossed CAG-ATDC mice with p48-Cre;LSL-KrasG12D mice (“KC” mice) (Hingorani et al. 2003) to generate p48-Cre;LSL-KrasG12D; CAG-ATDC mice, termed “AKC” mice.