Since stromal bone morphogenetic protein (BMP) signaling also plays a role in regulating the growth of intestinal epithelium and its inhibition leads to polyposis in mice [36], we examined and found comparable pSMAD1/5/8 in Lkb1 mutant and control mice (data not shown), suggesting BMP signaling is not affected in our model system. The gene discussed is STK11; the disease is polyposis.