The osteoid tumor area in Ctsk-CKO tibiae was mainly formed by GFP-positive cells by the age of 20 week (Figure 4C and Supplemental Figure 3B), indicating that the osteogenic tumor in Ctsk-CKO mice was caused by intrinsic Lkb1 deletion in Ctsk-Cre–expressing cells. The gene discussed is STK11; the disease is neoplasm.