RB1CC1 and lymphangioma: To study the role of autophagy in the development of LM and progression to LAS driven by Tsc1 deletion and consequent mTORC1 hyper-activation in ECs, we crossed Fip200f/f mice27 with Tsc1f/f;Scl-Cre mice17 to generate Tsc1f/f;Fip200f/f;Scl-Cre mice for deletion of an essential autophagy gene Fip200 in the previously described Tsc1iΔEC mouse model of human LAS17.