Sirolimus (rapamycin), an mTOR inhibitor, has shown efficacy in stabilizing lung function, reducing serum vascular endothelial growth factor-D (VEGF-D) levels, resolving chylous effusions and improving 6-min walking distances and is associated with an improved quality of life in patients with LAM [14,15,16,17]. Here, VEGFD is linked to lymphangioleiomyomatosis.