Previous studies addressing this issue showed that mono- or biallelic deletion of Lkb1 from smooth muscle, using a conditional Lkb1 allele and recombination mediated by SM-CreERT2(ki), led to smaller polyps (~0.6 mm) than those seen in Lbk1+/− mice (1.5–10 mm), and not to large occluding polyps or to intestinal obstruction (Katajisto et al., 2008). The gene discussed is STK11; the disease is intestinal obstruction.