SHH and neoplasm: In a study with doxycycline-inducible expression of mutant KRASG12D (Kirsten rat sarcoma) in pancreatic cells using mouse models of early PDAC showed that transformed tumor cells released Granulocyte/Macrophage Colony Stimulating Factor (GM-CSF) and the growth morphogen protein sonic hedgehog (SHH), a principal ligand of the HH (Hedgehog) signaling pathway [25].