TSC and LAM lesions are believed to share the common feature of elevated mTOR pathway signaling, ultimately as a consequence of inactivating mutations in TSC1 or TSC2 (Green et al., 1994; Niida et al., 2001; Han et al., 2004; Henske and McCormack, 2012). Here, TSC2 is linked to lymphangioleiomyomatosis.