KRAS and Patent ductus arteriosus: Huang et al. (2014) showed that oncogenic Kras requires GTP loading for enhanced activity. Presumably, Rgs16::GFP is marking the precise location of, and perhaps the cells directly engaged in, receptor-dependent activation of KrasG12D signaling. Thus, these in vivo reporter mice could help to identify drugs that directly or indirectly inhibit KrasG12D activation during ADM, PanIN formation and PDA progression.