LAM cells can be found throughout the lymphatics in LAM patients, and their expression of VEGF-C and VEGF-D along with VEGF receptor-3 indicates their lymphangiogenic potential (Glasgow et al., 2012), indicating that the extensive network of lymphatics may serve as the primary niche for LAM cells and facilitates their spread. The gene discussed is TSC1; the disease is lymphangioleiomyomatosis.